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Delphi

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Peces de codi

Drawing a line

TCanvas.MoveTo() method takes two arguments, x and y, that represent the point where the line would start. To draw a line from point A to point B, you use the TCanvas.LineTo() method. This method also takes two arguments that specify the end point of the line.

procedure TForm1.FormPaint ( Sender: TObject ) ; begin Canvas.MoveTo ( 20, 15 ) ; Canvas.LineTo ( 150, 245 ) ; end;

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Reposicionament del (0,0) i del sentit creixent dels eixos :

SetMapMode( Image1.Canvas.Handle, MM_ISOTROPIC); SetViewportOrgEx( Image1.Canvas.Handle, 20, 180, nil) ; // (X,Y)
XY

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Canvas objects
Canvas.TextOut ( 5, 10, 'Transparent text' ) ; Canvas.Brush.Style := bsClear ; Canvas.Brush.Color := Canvas.Pen.Width := 1 ; Canvas.Pen.Color := Canvas.MoveTo ( Rect.Left, Y ) ; Canvas.LineTo ( Rect.Right, Y ) ; Canvas.Rectangle ( 0, 0, 200, 200 ) ; Canvas.Ellipse ( 0, 0, 200, 200 ) ;
PaintBox vs Image

Like with a TPaintBox, you can draw items on the canvas of a TImage control. But a TImage will refresh itself when necessary; the image will be redrawn without your help if the image is moved or minimized or has other forms popup over it. This is not the case with a TPaintBox: it's the programmer's job to make sure that it knows how to "repaint" itself. Try this code :

procedure TForm1.Button1Click(Sender: TObject); begin with PaintBox1.Canvas do begin Brush.Style := bsSolid; Brush.Color := clBlue; Rectangle(0, 0, PaintBox1.Width, PaintBox1.Height); end; with Image1.Canvas do begin Brush.Style := bsSolid; Brush.Color := clBlue; Rectangle(0, 0, Image1.Width, Image1.Height); end; end;

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Kuki at Delphi : 
 MyTime := FormatDateTime('"Actual Time is "' + LongTime Format, Now);

 Edit1.Text := TimeToStr(Time) + ' - Has pitjat el boto 2.' ;
Get Environment Var : szMqServer := GetEnvironmentVariableAsString ( 'MQSERVER' ) ;
function GetEnvironmentVariableAsString ( const VarName : string ) : string ; var bsz : Integer ; begin // Get required buffer size (including terminal #0) bsz := GetEnvironmentVariable ( PChar ( VarName ), nil, 0 ) ; if bsz > 0 then begin // Read env var value into result string SetLength ( Result, bsz - 1 ) ; GetEnvironmentVariable ( PChar ( VarName ), PChar ( Result ), bsz ) ; end else // No such environment variable Result := '' ; end;

Una altra aportació d'en Pere ! I una altra a continuació ...

szMQServer := GetEnvironmentVariable ( 'MQSERVER' ) ;
Execution window position

Delphi situa la main form depenent de la property Position. Quan és poDesigned, Delphi crea la finestra en el lloc en que l'has situat quan l'estàs dissenyant. Pots provar poScreenCenter, o poDefaultSizeOnly.

També pots restaurar la posició on l'ha deixat l'usuari la darrera vegada que ha executat el teu programa. Per fer-ho, has de guardar la posició en el moment de tancar la finestra i restaurar-la en obrir-se un altre cop. Per exemple, així...

procedure TmainForm.FormClose(Sender: TObject; var Action: TCloseAction); var iniFile: TInifile; begin iniFile := TIniFile.Create('my.ini'); iniFile.WriteInteger('Position', 'Left', MainForm.Left); iniFile.WriteInteger('Position', 'Top', MainForm.Top); iniFile.WriteInteger('Position', 'Width', MainForm.Width); iniFile.WriteInteger('Position', 'Height', MainForm.Height); iniFile.free; end; procedure TmainForm.FormShow(Sender: TObject); var iniFile: TIniFile; begin iniFile := TIniFile.Create('my.ini'); MainForm.Left := iniFile.ReadInteger ('Position', 'Left', 10); MainForm.Top := iniFile.ReadInteger('Position', 'Top', 10); MainForm.Width := iniFile.ReadInteger('Position', 'Width', 500); MainForm.Height:= iniFile.ReadInteger('Position', 'Height', 500); iniFile.Free; end;
How to end a Delphi program

If you are used to working in the form unit, you know you need to call Close or Application.Terminate to cause your program to end.

procedure TForm1.Button1Click(Sender: TObject); begin close; end;

Lo més estandard és el mètode Close de la main form. D'aquesta manera executes tots els handlers ....

  • The Close method calls CloseQuery
  • CloseQuery calls the form's OnCloseQuery event (if it is defined)
  • If OnCloseQuery event returns True (or it is not defined), then the Close method calls form's OnClose event (if it is defined)
  • If this is the MainForm and OnClose returns anything other than caNone (or it is not defined), then Close calls Application.Terminate to actually close the form.
  • If this is not the MainForm, and OnClose returns caHide (or it is not defined), then the Close method calls Hide.

Una altra manera és Application.Terminate, però no crida onCloseQuery ni onClose. Mata l'aplicació.

Finalment, pots passar dels mètodes de les classes i anar directament a matar el procés, usant Halt. No executa cap codi. Només en casos extrems de "Abormal Termination".

How to hide from Close Program

When you press the Ctrl-Alt-Del key combination the "Close Program" dialog box pops up. One simple way to hide your program from that dialog (the Task Manager dialog) is to clear the Application object's Title. If a program's main window does not have a title, Windows XX does not put the program in the "Close Program" dialog window. Remember that in Delphi the so called "main" window is not the Application window. The best place to clear the Title property is inside the Project's source code. To see the Project source, select Project|View Source in the IDE. After the Application.Initialize add the bolded line:

Application.Initialize; Application.Title := ''; Application.CreateForm(TForm1, Form1) ;
MEMORYSTATUS
procedure TForm1.Button1Click(Sender: TObject) ; var MemoryStatus: TMemoryStatus ; begin MemoryStatus.dwLength := SizeOf(MemoryStatus) ; GlobalMemoryStatus(MemoryStatus) ; with MemoryStatus do begin { Size of MemoryStatus record } say(IntToStr(dwLength) + ' Size of ''MemoryStatus'' record') ; { Per-Cent of Memory in use by your system } say(IntToStr(dwMemoryLoad) + '% memory in use') ; {The amount of Total Physical memory allocated to your system.} say(IntToStr(dwTotalPhys) + ' Total Physical Memory in bytes') ; { The amount available of physical memory in your system. } say(IntToStr(dwAvailPhys) + ' Available Physical Memory in bytes') ; { The amount of Total Bytes allocated to your page file } say(IntToStr(dwTotalPageFile) + ' Total Bytes of Paging File') ; { The amount of available bytes in your page file } say(IntToStr(dwAvailPageFile) + ' Available bytes in paging file') ; { The amount of Total bytes allocated to this program (generally 2 gigabytes of virtual space) } say(IntToStr(dwTotalVirtual) + ' User Bytes of Address space') ; { The amount of available bytes that is left to your program to use } say(IntToStr(dwAvailVirtual) + ' Available User bytes of address space') ; end; end;

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O, en una versió més reduida (Unit "mem_sag") :

function Mostrar_Memory_Status ( ) : string ; var MemoryStatus: TMemoryStatus ; begin MemoryStatus.dwLength := SizeOf ( MemoryStatus ) ; GlobalMemoryStatus ( MemoryStatus ) ; with MemoryStatus do begin Mostrar_Memory_Status := IntToStr ( dwAvailVirtual ) ; end ; // with end ; // Mostrar_Memory_Status 
 if paramcount > 0 then
   for i := 1 to paramcount do
     begin
       szStatus := '>>> Param (' + IntToStr(i) + ') is (' + paramstr(i) + ').' ;
       Posar_Status ( szStatus ) ;
   end ;

 if ( ParamCount > 0 )
 then begin
   fInName := ParamStr(1) ;
 end ; { if ... }
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Beep
procedure PlayBeep ( ActionType: TMsgDlgType ) ; var mb: dWord; begin case ActionType of mtInformation: mb := MB_ICONASTERISK ; // SystemAsterisk mtWarning: mb := MB_ICONEXCLAMATION ; // SystemExclamation mtError: mb := MB_ICONHAND ; // SystemHand mtConfirmation: mb := MB_ICONQUESTION ; // SystemQuestion mtCustom: mb := MB_OK ; // SystemDefault else mb:= $0FFFFFFFF ; // Standard beep using the computer speaker end; MessageBeep(mb) ; end;

url

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File Search
procedure TForm1.Button1Click(Sender: TObject); var Search_Result : TSearchRec ; INstring, OUTstring : string ; begin INstring := Edit1.Text ; StringGrid1.RowCount := 0 ; debugMsg ( 'Boto-1. Busquem {' + INstring + '}.' ) ; if FindFirst ( INstring, faAnyFile, Search_Result ) = 0 then begin repeat OUTstring := Search_Result.Name + ' ' + IntToStr ( Search_Result.Size ) + ' ' + DateTimeToStr ( FileDateToDateTime( Search_Result.Time) ) ; StringGrid1.RowCount := StringGrid1.RowCount + 1; StringGrid1.Cells [ 1, StringGrid1.RowCount - 1 ] := Search_Result.Name ; StringGrid1.Cells [ 2, StringGrid1.RowCount - 1 ] := IntToStr( Search_Result.Size ) ; debugMsg ( '+++ Trobat {' + OUTstring + '}.' ) ; until FindNext ( Search_Result ) <> 0 ; FindClose ( Search_Result ) ; end else begin debugMsg ( '--- No trobat.' ) ; end ; end; // Button1 Click
procedure TForm1.Button2Click(Sender: TObject); var OriginDir, FileToFind : string ; begin OriginDir := 'c:\Program Files\MyOrigin\' ; debugMsg ( 'Boto-2. Busquem {' + OriginDir + '}.' ) ; FileToFind := FileSearch ( Edit1.Text, OriginDir ) ; // Name DirList if FileToFind = '' then ShowMessage('Couldn''t find ' + Edit1.Text + '.') else ShowMessage('Found ' + FileToFind + '.'); end;
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Hex Dump
const HexN: array [ 0..15 ] of char = '0123456789ABCDEF' ; function HexB ( b: byte ) : string ; begin HexB:= HexN [ b shr 4 ] + HexN [ b and $0F ] ; end; function HexC ( c: char ) : string ; begin HexC := HexB ( byte(c) ) ; end; function HexW ( w: word ) : string ; begin HexW := HexB ( Hi(w) ) + HexB ( Lo(w) ) ; end; function HexDW ( i: Integer ) : string ; begin HexDW := HexW ( word (i shr 16) ) + HexW ( word (i) ) ; end;
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Port Paralel
procedure TForm1.ScrollBar1Change ( Sender : TObject ) ; var bWriteMe, bErr : byte ; function Out32 ( wAddr : word; bOut : byte ) : byte ; stdcall ; external 'inpout32.dll' ; begin bWriteMe := ScrollBar1.position ; Label1.caption := IntToStr ( bWriteMe ) ; bErr := ( Out32 ( $378, bWriteMe ) ) ; end ;

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Get INPOUT32.DLL here ; good description, how it works,
Copy inpout32.dll to system directory, system32\Drivers folder.

Programming For Parallel Port Device {interessant : VC++, Delphi, lots of code}

Standard Routines

The table below lists frequently used procedures and functions found in Borland product libraries. This is not an exhaustive inventory of standard routines.

Procedure or function Description
Addr Returns a pointer to a specified object.
AllocMem Allocates a memory block and initializes each byte to zero.
ArcTan Calculates the arctangent of the given number.
Assert Raises an exception if the passed expression does not evaluate to true.
Assigned Tests for a nil (unassigned) pointer or procedural variable.
Beep Generates a standard beep.
Break Causes control to exit a for, while, or repeat statement.
ByteToCharIndex Returns the position of the character containing a specified byte in a string.
Chr Returns the character for a specified integer value.
Close Closes a file.
CompareMem Performs a binary comparison of two memory images.
CompareStr Compares strings case sensitively.
CompareText Compares strings by ordinal value and is not case sensitive.
Continue Returns control to the next iteration of for, while, or repeat statements.
Copy Returns a substring of a string or a segment of a dynamic array.
Cos Calculates the cosine of an angle.
CurrToStr Converts a currency variable to a string.
Date Returns the current date.
DateTimeToStr Converts a variable of type TDateTime to a string.
DateToStr Converts a variable of type TDateTime to a string.
Dec Decrements an ordinal variable or a typed pointer variable.
Dispose Releases dynamically allocated variable memory.
ExceptAddr Returns the address at which the current exception was raised.
Exit Exits from the current procedure.
Exp Calculates the exponential of X.
FillChar Fills contiguous bytes with a specified value.
Finalize Uninitializes a dynamically allocated variable.
FloatToStr Converts a floating point value to a string.
FloatToStrF Converts a floating point value to a string, using specified format.
FmtLoadStr Returns formatted output using a resourced format string.
FmtStr Assembles a formatted string from a series of arrays.
Format Assembles a string from a format string and a series of arrays.
FormatDateTime Formats a date-and-time value.
FormatFloat Formats a floating point value.
FreeMem Releases allocated memory.
GetMem Allocates dynamic memory and a pointer to the address of the block.
Halt Initiates abnormal termination of a program.
Hi Returns the high-order byte of an expression as an unsigned value.
High Returns the highest value in the range of a type, array, or string.
Inc Increments an ordinal variable or a typed pointer variable.
Initialize Initializes a dynamically allocated variable.
Insert Inserts a substring at a specified point in a string.
Int Returns the integer part of a real number.
IntToStr Converts an integer to a string.
Length Returns the length of a string or array.
Lo Returns the low-order byte of an expression as an unsigned value.
Low Returns the lowest value in the range of a type, array, or string.
LowerCase Converts an ASCII string to lowercase.
MaxIntValue Returns the largest signed value in an integer array.
MaxValue Returns the largest signed value in an array.
MinIntValue Returns the smallest signed value in an integer array.
MinValue Returns smallest signed value in an array.
New Creates a dynamic allocated variable memory and references it with a specified pointer.
Now Returns the current date and time.
Ord Returns the ordinal integer value of an ordinal-type expression.
Pos Returns the index of the first single-byte character of a specified substring in a string. [url]
Pred Returns the predecessor of an ordinal value.
Ptr Converts a value to a pointer.
Random Generates random numbers within a specified range.
ReallocMem Reallocates a dynamically allocatable memory.
Round Returns the value of a real rounded to the nearest whole number.
SetLength Sets the dynamic length of a string variable or array.
SetString Sets the contents and length of the given string.
ShowException Displays an exception message with its address.
ShowMessage Displays a message box with an unformatted string and an OK button.
ShowMessageFmt Displays a message box with a formatted string and an OK button.
Sin Returns the sine of an angle in radians.
SizeOf Returns the number of bytes occupied by a variable or type.
Sqr Returns the square of a number.
Sqrt Returns the square root of a number.
Str Converts an integer or real number into a string.
StrToCurr Converts a string to a currency value.
StrToDate Converts a string to a date format (TDateTime).
StrToDateTime Converts a string to a TDateTime.
StrToFloat Converts a string to a floating-point value.
StrToInt Converts a string to an integer.
StrToTime Converts a string to a time format (TDateTime).
StrUpper Returns an ASCII string in upper case.
Succ Returns the successor of an ordinal value.
Sum Returns the sum of the elements from an array.
Time Returns the current time.
TimeToStr Converts a variable of type TDateTime to a string.
Trunc Truncates a real number to an integer.
UniqueString Ensures that a string has only one reference. (The string may be copied to produce a single reference.)
UpCase Converts a character to uppercase.
UpperCase Returns a string in uppercase.
VarAsType Converts a variant to specified type.
VarCast Converts a variant to a specified type, storing the result in a variable.
VarClear Clears a variant.
VarCopy Copies a variant.
VarToStr Converts variant to string.
VarType Returns type code of specified variant.

Delphi String Types
  • Pascal Strings : use length()
  • Null-terminated Strings : use strlen()

String Types In Delphi

Help : Find(string) + "About string types"

A string represents a sequence of characters

var MyString : string ;

The standard function Length returns the number of characters in a string. The SetLength procedure adjusts the length of a string.

You can index a string variable just as you would an array. First char is "1" and last is "length()".

You can assign the value of a string constant--or any other expression that returns a string--to a variable. The length of the string changes dynamically when the assignment is made. Examples:

MyString := 'Hello world!'; MyString := 'Hello ' + 'world'; MyString := MyString + '!'; MyString := ' '; { space } MyString := ''; { empty string }

Help : Index(string) + null-terminated strings

To manipulate null-terminated strings, it is often necessary to use pointers.

var P: PChar; ... P := 'Hello world!';

Points P to an area of memory that contains a null-terminated copy of "Hello world!". This is equivalent to

const TempString: array[0..12] of Char = 'Hello world!'#0; var P: PChar; ... P := @TempString[0];
String Formatting Routines
FmtLoadStr function
Returns formatted output using a resourced format string.
FmtStr procedure
Assembles a formatted string using a format string and an array of arguments.
Format function
Returns a formatted string assembled from a format string and an array of arguments.

URL

FormatBuf function
Formats the arguments from an array, placing the result in a buffer.
FormatMaskText function
Returns a string formatted using an edit mask.
GetFormatSettings procedure
Resets the date and number format parameters to initial values.
GetLocaleFormatSettings procedure
Populates a TFormatSettings data structure.
StrFmt function
Formats entries in an array.
StrLFmt function
Formats a series of arguments from a specified open array into a buffer.
WideFormat function
Returns a formatted Unicode string assembled from a format string and an array of arguments.
WideFormatBuf function
Formats the arguments from an array, placing the result in a buffer.
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STRING functions

What is the Delphi equivalent on C+ " strncpy ?

procedure Move ( const SourcePointer; var DestinationPointer; CopyCount : Integer ) ; [url]

function StrCopy ( Dest: PChar; const Source: PChar) : PChar ;

Sample :

procedure TForm1.Button1Click(Sender: TObject); var Buffer: PChar ; begin GetMem ( Buffer, Length ( Label1.Caption ) + Length ( Edit1.Text ) + 1 ) ; StrCopy ( Buffer, PChar ( Label1.Caption ) ) ; // destinacio, origin. StrCat ( Buffer, PChar ( Edit1.Text ) ) ; Label1.Caption := Buffer ; Edit1.Clear ; FreeMem ( Buffer ) ; end;

function StrpCopy ( Dest: PChar; const Source: string ) : PChar ;
Use StrPCopy to change a Pascal string into a PChar, or zero-based Char array. [url]

Example :

uses Sysutils ; var A : array [0..79] of Char ; S : string ; begin S := 'Honk if you know Basile' ; StrpCopy ( A, S ) ; // destination (array), origin (string). Canvas.textout ( 10, 10, string(A) ) ; end ;

*** RTL Reference ***

How to display
ShowMessage ( szSAG + IntToStr(lng) ) ; Application.MessageBox ( SecondHalf, 'Second Half', 0 ) ; // Did the directory get created OK? error := IOResult; if error = 0 then ShowMessage('Directory created OK') else ShowMessageFmt('Directory creation failed with error %d',[error]);
Label29.Caption := Producte + Versio + Autor + DateToStr( Date() ) ;

How do we create Windows Services in Delphi?
Easy : select the menu items File, New, Other and select "Service Application" and click OK.

Console Application

3 ways to do it :

  • en Delphi fent File | New | Other... | Console Application

  • creant un prg.pas que contingui la directive {$APPTYPE CONSOLE}
    program prg; {$APPTYPE CONSOLE} begin writeln('Hello, world!"); end.
    i compilant-lo normal :
    c:\temp>"\program files\borland\delphi7\bin\dcc32" prg

  • creant un prg.pas
    program prg; begin writeln('Hello, world!"); end.
    i compilant-lo amb el flag -CC
    c:\temp>"\program files\borland\delphi7\bin\dcc32" -CC prg

Basic File I/O
var fileInputData : TextFile ; iIORC : integer ; iNumLines : integer ; InputDataLine : string ; begin AssignFile ( fileInputData, kIniFilename ) ; FileMode := 0 ; // Set file access to read only {$I-} // turn OFF I/O checking. "{$IOChecks off}" Reset ( fileInputData ) ; iIORC := IOResult ; [url] iNumLines := 0 ; while not EOF ( fileInputData ) do begin Readln ( fileInputData, InputDataLine ) ; iNumLines := iNumLines + 1 ; debugMsg ( 'Linea (' + IntToStr(iNumLines) + ') = {' + InputDataLine + '}.' ) ; end ; // eof(fileInputData) CloseFile ( fileInputData ) ; {$I+} // turn ON I/O checking debugMsg ( 'Llegides (' + IntToStr(iNumLines) + ') linies.' ) ;
File I/O - Delphi Examples

There are 3 basic methods to perform File I/O

  • Use Pascal file variables
  • Use Windows API function wrappers
  • Use Windows API functions

url

FileMode
NormalMode = $02 ; { ---- 0010 } ReadOnly = $00 ; { ---- 0000 } WriteOnly = $01 ; { ---- 0001 } ReadWrite = $02 ; { ---- 0010 } DenyAll = $10 ; { 0001 ---- } DenyWrite = $20 ; { 0010 ---- } DenyRead = $30 ; { 0011 ---- } DenyNone = $40 ; { 0100 ---- } NoInherit = $70 ; { 1000 ---- }

(filutilh.inc) : const fmShareDenyNone = $0040 ;

I/O rc's
  • 30 = ERROR_READ_FAULT
    Occurs when the system cannot read from the specified device.
  • 31 = ERROR_GEN_FAILURE
    Occurs when a device attached to the system is not functioning.
  • 32 = ERROR_SHARING_VIOLATION
    The process cannot access the file because it is being used by another process.
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Window control
if ( WindowState = wsNormal ) or ( WindowState = wsMaximized ) then WindowState := wsNormal ;
Full Screen
procedure TForm1.FormCreate ( Sender: TObject ) ; begin BorderStyle := bsNone ; // turn off the form's border WindowState := wsMaximized ; // maximize window to screen size end;
Debug or Trace ListBox

Fitxer "SAG_debug.pas" a T42:\\Delphi\Units\. Posar "SAG_debug," al "Uses" ...

procedure debugMsg ( s: string ) ; const MaxNumofItems = 1000 ; NumItemstoDelete = 500 ; var i : integer ; begin with Form1.Listbox2 do begin if Items.Count > MaxNumofItems then begin for i:=1 to NumItemstoDelete do Items.Delete(0); end; Items.Add ( dateTimeToStr ( now ) + ' ['+inttostr(items.count)+'] ' + s ) ; ItemIndex := Count - 1 ; // display last item (maybe scrolled) ItemIndex := -1 ; // no focus at all = remove focus end; end ; (* debugMsg *)
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Timer
procedure debugMsg ( s:string ) ; begin if not bLB_Enabled then Exit ; with Form1.ListBox1 do begin Items.add ( dateTimeToStr ( now ) + ' ' + s ) ; ItemIndex := Count - 1 ; // focus on last item ItemIndex := -1 ; // no focus end; end; procedure TForm1.MyShow(Sender: TObject); begin Timer1.Enabled := False ; iInterval := 1000 ; Timer1.Interval := iInterval ; debugMsg ( 'Interval is (' + IntToStr(iInterval) + ').' ) ; end; procedure TForm1.Timer1Timer(Sender: TObject); begin debugMsg ( 'Hola.' ) ; end; procedure TForm1.Button1Click(Sender: TObject); begin Timer1.Enabled := not (Timer1.Enabled) ; if Timer1.Enabled then Button1.Caption := 'Stop.' else Button1.Caption := 'Start.' ; end; end.
Time Period
uses DateUtils ; var tim_Inicio_Periodo, tim_Final_Periodo : TDateTime ; i64_Lapso : Int64 ; tim_Inicio_Periodo := Time() ; repeat tim_Final_Periodo := Time() ; i64_Lapso := MilliSecondsBetween ( tim_Final_Periodo, tim_Inicio_Periodo ) ; until ( i64_Lapso > k_Thread_Delay_mSg ) ;
PageControl
Semaphores & Mutexes

There is one very big difference between semaphores and mutexes, however. While a mutex can be acquired by no more than one thread or process at a time, semaphores can be designed to allow two or more threads to acquire the semaphore simultaneously.

A thread gets ownership of a mutex by specifying a handle of the mutex in one of the wait functions, as WaitForSingleObject. The ReleaseMutex function releases ownership of the specified mutex object.

  • Using Semaphores Part 1, part 2
  • Mutex sample : "Program is already Running !".

    var mHandle: THandle; // Mutexhandle initialization mHandle := CreateMutex(nil, True, 'XYZ'); if GetLastError = ERROR_ALREADY_EXISTS then begin ShowMessage('Program is already running!'); halt; end; finalization if mHandle <> 0 then CloseHandle(mHandle) end.

Q:
How can I turn a regular Delphi application into a service for a Windows NT4 server? The meaning for this is that the program should run when the server is rebooted and even when the server is not logged on. So putting the program in startup folder is not enough.

A:
With Delphi 5, this has become very simple. Just go to 'File' -> 'New' -> 'Service Application'. It will create a regular project source with one main 'form', which is derived from TService.

The TService class encapsulates a Windows NT service in an NT service application. A service is accessed via the Service Control Manager. It is usually started during boot time or manually in the control panel 'Services' applet.

The code will look as shown in the example below and consult the online help about TService. You may want to handle the OnExecute event. 

type
  TService1 = class(TService)
  private
    { private declarations }
  public
    function GetServiceController: TServiceController; override;
  end;

URL
See also List all installed services and drivers

Delphi 5 service
An NT service application is a 32-bit Windows application that can run without requiring a user to be logged on. In fact, NT service applications seldom interact with the desktop at all.
As you would expect, implementing an NT service requires a special technique. Fortunately, Delphi 5 takes care of most of the service implementation details by introducing two special icons in the Object Repository. To open the Object Repository, choose New from the File menu.
You'll notice a Service icon and a Service Application icon. The former creates only a new Service unit; the latter creates a new Delphi project with a Service unit. Use the Service Application icon and save your project in ServProj.dpr and the unit in Server42.pas. If you take a close look at your main project file, you'll see the following code, which looks like a regular Delphi project: 

 program ServProj;
 uses
 SvcMgr,
 Server42 in 'Server42.pas'{Service1: TService};

 {$R *.RES}
 begin
  Application.Initialize;
  Application.CreateForm(TService1, Service1);
  Application.Run;
 end.
However, there are some differences in this code. For example, the Forms unit has been replaced by the SvcMgr unit. As a result, the Application variable is not of type TApplication but of type TServiceApplication (taking care of the NT service application details for us). If you switch to the Server42 unit, you’ll see that it looks similar to a Delphi data module. And as with a data module, you can add just about any nonvisual component to the new service. But remember that you’re restricted to nonvisual components; you'll get an exception "Controls Cannot Be Added To A Service" message if you try to drop a visual component.

URL

Few links :

  • Open Directory Project : 
     Top: World: Español: Computadoras: Programación: Lenguajes: Delphi: Guías y tutoriales
 Computers : Programming : Languages : Delphi : Tutorials
 Computers : Programming : Languages : Delphi : Commercial Services > Training Courses
 Computers : Programming : Languages : Delphi : FAQs
  • Google + "Delphi Tutorials"

  • YOV404 + search + "Delphi"

  • Delphi sites rating

  • 3 levels of Tutorials + links

  • Teach Yourself Delphi in 21 days - HTML

  • Delphi in a Nutshell - PDF.

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How to call a DOS function from Delphi
uses ShellApi; function DosCopy( src, dest: string ) : Integer; var bat: TextFile; batfile: string; begin if FileExists(src) then begin { Build a batch file that contains copy <sourcefile> <destfile> exit The exit command closes the dos window } BatFile := ExtractFilePath(ParamStr(0)) + 'cpy.bat'; AssignFile(bat, batfile); Rewrite(bat); WriteLn(bat, 'copy ' + src + ' ' + dest); WriteLn(bat, 'exit'); CloseFile(bat); // Now Execute the batch file Result := ShellExecute(0, 'open', 'cmd.exe', PChar('/k ' + batfile), '', SW_SHOW); // the /k tells cmd to carry on after executing the batch file // I've used SW_SHOW in this example so that you see the window running // normally you would use SW_HIDE end; end; procedure TForm7.Button1Click(Sender: TObject); var src, dest, msg: string; ret: Integer; begin src := 'c:\windows\win.ini'; dest := ExtractFilePath(ParamStr(0)) + 'win.ini'; ret := DosCopy(src, dest); case ret of 0: msg := ' The operating system is out of memory or resources.'; ERROR_FILE_NOT_FOUND: msg := ' The specified file was not found.'; ERROR_PATH_NOT_FOUND: msg := ' The specified path was not found.'; ERROR_BAD_FORMAT: msg := ' The .exe file is invalid (non-Microsoft Win32 .exe or error in .exe image).'; SE_ERR_ACCESSDENIED: msg := ' The operating system denied access to the specified file.'; SE_ERR_ASSOCINCOMPLETE: msg := ' The file name association is incomplete or invalid.'; SE_ERR_DDEBUSY: msg := ' The Dynamic Data Exchange (DDE) transaction could not be completed because other DDE transactions were being processed.'; SE_ERR_DDEFAIL: msg := ' The DDE transaction failed.'; SE_ERR_DDETIMEOUT: msg := ' The DDE transaction could not be completed because the request timed out.'; SE_ERR_DLLNOTFOUND: msg := ' The specified DLL was not found.'; SE_ERR_NOASSOC: msg := ' There is no application associated with the given file name extension. This error will also be returned if you attempt to print a file that is not printable.'; SE_ERR_OOM: msg := ' There was not enough memory to complete the operation.'; SE_ERR_SHARE: msg := ' A sharing violation occurred'; end; if (ret = 32) // This is the documented OK return or

Delphi items

File extensions
  • .bpg - a project group
  • .bpl - compiled package
  • .cfg - the project configuration file. Contains compiler and linker settings.
  • .dcu - Delphi Compiled Unit, compiled binary object files.
    *** regenerated => can be removed IF Source and Compiler are available ***
  • .dfm - the form file. It is a binary resource file in disguise. Enviar amb ".pas".
  • .dof - the project options file (set in the Project Options dialog)
  • .dpk - Delphi package source file
  • .dpr - the project source file. Describes the individual projects, files and associated options.
  • .dsk - the project desktop file. Created only if you turn on the option to save your desktop (Environment Options)
  • .exe - the final executable program.
  • .pas - object Pascal source files. There will be one for each unit.
  • .res - the compiled binary resource file.
  •  

Delphi wants a DPR file as the project's root.

To Copy/Rename a complete project, only DPR, PAS and DFM files are required.

DFM files can be saved in Binary or Text format. Text is better, and is selected by ... selecting "Text DFM" when viewing a Form and left button is used.

URL.

Dialog Boxes the Delphi way

A modal dialog box is one that must be dismissed before the user can continue using the application A modeless dialog box is one that allows the user to continue to work with the application while the dialog box is displayed. To execute a modal dialog box, you call the ShowModal method of TForm. To create a modeless dialog box, you call the Show method.

url

To create an MDI (Multiple Document Interface) application in Delphi, you must set the main form's FormStyle property to fsMDIForm. Each of the MDI child windows must have the FormStyle property set to fsMDIChild.
If you have multiple components selected on the form, the Object Inspector shows all the properties that those components have in common. You can use this feature to modify the properties of several components at one time.
  • a form is Delphi's term for a window you can edit with Delphi's GUI builder. A form description is stored in a .dfm file, which contains the form's layout, contents and properties.
  • a unit has two parts : interface and implementation. The interface part declares the types, variables, constants and routines that are visible to other units. The implementation section provides the guts of the routines declared in the interface section. The implementation section can have additional declarations that are private to the unit's implementation. Thus, units are Delphi's primary means of information hiding.
    Every unit can have an initialization and a finalization section.
  • a Delphi GUI application will contain at least two units. The project source unit contains the project source code (it will have an extension of .dpr)
    The second type of unit a delphi GUI application always has is the main form's unit - this type of unit has a filename extension of .pas
  • in a GUI application, you cannot use standard Pascal I/O procedures, because there is no input device to read and no output device to write to. Instead, you can compile a console application, which can read and write using standard Pascal I/O routines.
  • Delphi's PChar type is the equivalent of char * in C or C++.
  • any non-zero value is considered true, zero is false.
  • the Format function enables you to build a string by passing a format string and additional arguments. 
     var
  X,Y : Integer;
 begin
  X := 20; Y := 5;
  Label1.Caption := Format(`%d + %d = %d', [X, Y, X + Y]);
 end;
  • TRect represents the dimensions of a rectangle. By convention the top and left edges are considered inside the rectangle, and the bottom and right edges are considered outside the rectangle. This convention allows the width of the rectangle to be Right - Left, and the height to be Bottom - Top.
  • the type Pointer is a generic pointer type, equivalent to void * in C or C++.
  • to take the address of a variable, use Addr, equivalent to & in C or C++.
  • file I/O
    • Append - open an existing file for appending
    • AssignFile or Assign - assign a filename to a File or TextFile variable.
    • BlockRead - read data from a file.
    • BlockWrite - write data to a file.
    • CloseFile or Close - close an open file.
    • Eof - returns true for end of file.
    • Erase - delete a file.
    • FilePos - return the current file position.
    • FileSize - return the size of a file, in records.
    • Read - read formatted data from a file or a text file.
    • ReadLn - read a line of data from a text file.
    • Rename - rename a file.
    • Reset - open a file for reading.
    • Rewrite - open a file for writing, erasing the previous contents.
    • Seek - change the file position.
    • Write - write formatted data.
    • WriteLn - write a line of text.
    When a file is open with Reset, the FileMode variable dictates the mode for opening the file.
    • 2 = read and write access.
    • 0 = read only.
    • 1 = write only.
    Delphi specifics :
    • standard Pascal procedures Get and Put are not supported
    • better way to do file I/O : use streams
  • Delphi borrows a feature from the Eiffel language, namely the Result variable. Every function implicitly declares a variable, named Result, whose type is the function's return type. You can use this variable as an ordinary variable, and when the function returns, it returns the value of the Result variable. Using Result is more convenient than assigning a value to the function name, which is the standard Pascal way to return a function result. Because Result is a variable, you can get and use its value repeately.
  • think of a class as a record on steroids. Like a record, a class describes a type that comprises any number of parts, calles fields. Unlike a record, a class can also contain functions and procedures (called methods), and properties.
  • An object is a dynamic instance of a class. An object is always allocated dynamically, on the heap. When your program finishes using an object, it must explicitly free the object. Delphi does not have any automatic garbage collection.
  • the object is the chunk of memory where Delphi stores the values for all the object's fields. An object reference is a pointer to the object. The only way to use an object in Delphi is through an object reference.
  • Delphi's representation of a class is a read-only table of pointers to virtual methods about the class. A class reference is a pointer to the table. The most common use for a class reference is to create objects or to test the type of an object reference. The type of a class reference is called a metaclass.
  • A class declaration is a kind of type declaration. A class declaration describes the fields, methods and properties of the class. You can declare a class in an interface or implementation section of a unit, but the methods - like any other function or procedure - are defined in the implementation section.
  • a thread is a flow of control in a program, with its own stack, its own copy of the processor's registers, and related information.
  • a process is a collection of threads all running in a single address space. In a multithreaded application or library, you must be sure that the global variable IsMultiThread is True.

    Delphi in a Nutshell, page 95

  • tools :
    • command line compiler : dcc32.exe
    • object file dumper : tdump.exe
      Object files can be
      • in COFF - Common Object File Format
      • or OMF - Intel's Object Module Format
  • pg 96.
Available colors

If you specify TColor as a specific 4-byte hexadecimal number instead of using the constants defined in the Graphics unit, the low three bytes represent RGB color intensities for blue, green, and red, respectively. The value $00FF0000 represents full-intensity, pure blue, $0000FF00 is pure green, and $000000FF is pure red. $00000000 is black and $00FFFFFF is white.

Nice (Pere's) colors : Color := $DDEEFF ; and Color := $EFFFEF ;

Available objects
  • Standard
    • Frames
    • Main Menu (Menus)
    • Popup Menu (Menus)
    • Label (StdCtrls)
    • Edit (StdCtrls) - used to retrieve text that users type, but can also display text to the user.
      When only displaying text to the user, choose an edit control to allow users to select text and copy it to the Clipboard.
    • Memo (StdCtrls) - are appropriate for representing lengthy information, and is intended for moderate amounts of text.
    • Button (StdCtrls)
    • CheckBox (StdCtrls)
    • RadioButton (StdCtrls)
    • ListBox (StdCtrls) - displays a collection of items in a scrollable list that users can select, add, or delete.
    • ComboBox (StdCtrls)
    • ScrollBar (StdCtrls)
    • GroupBox (StdCtrls)
    • RadioGroup (ExtCtrls)
    • Panel (ExtCtrls)
    • ActionList (ActnList)
  • Additional
    • BitBtn (Buttons)
    • SpeedButton (Buttons)
    • MaskEdit (Mask)
    • StringGrid (Grids)
  • Win32
    • TabControl (ComCtrls)
    • PageControl (ComCtrls)
    • ImageList (Controls)
    • RichEdit (ComCtrls)
    • TrackBar (ComCtrls)
    • ProgressBar (ComCtrls)
    • UpDown (ComCtrls)
    • HotKey (ComCtrls)
  • System
  • Data Access
  • Data Controls
  • dbExpress
  • DataSnap
  • BDE
  • ADO
  • InterBase
  • WebServices
  • InternetExpress
  • Internet
    • ...
    • ClientSocket (from /bin/dclsockets70.bpl)
    • ServerSocket (from /bin/dclsockets70.bpl)
  • WebSnap
  • DecisionCube
  • Dialogs
  • Win 3.1
  • Samples
  • ActiveX
  • Rave
  • Indy Clients
  • Indy Servers
  • Indy Intercepts
  • Indy I/O Handlers
  • Indy Misc
  • COM+
  • InterBase Admin
  • IW Standard
  • IW Data
  • IW Client Side
  • IW Control
  • Servers

Edit controls display text to the user and allow the user to enter text.

Edit control properties
Property Description
Text Determines the text that appears in the edit box or memo control.
Font Controls the attributes of text written in the edit box or memo control.
AutoSize Enables the edit box to dynamically change its height depending on the currently selected font.
ReadOnly Specifies whether the user is allowed to change the text.
MaxLength Limits the number of characters in simple edit controls.
SelText Contains the currently selected (highlighted) part of the text.
SelStart, SelLength Indicate the position and length of the selected part of the text.

Lists present the user with a collection of items to select from. Several components display lists:

Form1.ListBox1.Style : TListBoxStyle ; lbOwnerDrawFixed, lbOwnerDrawVariable, lbStandard, lbVirtual, lbVirtualOwnerDraw Form1.ListBox1.Autocomplete : boolean ; Form1.ListBox1.Align : TAlign ; Form1.ListBox1.Anchors : TAnchors ; Form1.ListBox1.Color : TColor ; Form1.ListBox1.Items : TStrings ; Form1.ListBox1.Items.SaveToFile(Edit4.Text) ; save ListBox to File ListBox3.Items.LoadFromFile(OpenDialog1.Filename) ; load ListBox from File Form1.ListBox1.Style : TListBoxStyle ; Form1.ListBox1.Items.Count = number of items in list Form1.ListBox1.ItemIndex = selected item in list ( -1 = none ? ) i := LB1.ItemIndex ; // get selected item index. szOut := LB1.Items.Strings[i] ; // get selected text.
CheckBox versus RadioButton

CheckBox indicate a user selection, being multiple choices possible.

Radio buttons, also called option buttons, present a set of mutually exclusive choices.

CheckBox :

  • init : "CheckBox1.Checked := false ;"
  • on click : "bLB_Enabled := CheckBox1.Checked ; // set new value
String Grid
sg.ColCount := 2 ; sg.RowCount := 9 ; sg.FixedCols := 0 ; sg.FixedRows := 1 ; sg.Cells[0,0] := 'Centro Comercial' ; sg.Cells[1,0] := 'Tiempo de Respuesta' ;
Progress Bar

Important settings :

  • use Step := 5 ;
  • use Smooth := true ;
procedure TForm1.My_Init(Sender: TObject); // es posa al "OnCreate()" ! begin Timer1.Interval := 100 ; Timer1.Enabled := true ; ProgressBar1.Smooth := true ; ProgressBar1.Step := 1 ; iCnt := 0 ; ProgressBar1.Position := 0 ; end; procedure TForm1.Timer1Timer(Sender: TObject); var iRed, iGreen, iBlue, iColor, iOut, iOut2 : integer ; iSeg, iDec : integer ; begin ProgressBar1.StepIt ; iCnt := iCnt + 1 ; if ( iCnt >= 100 ) then iCnt := 0 ; iSeg := iCnt div 10 ; iDec := iCnt mod 10 ; Label2.Caption := ' {' + IntToStr(iSeg)+','+IntToStr(iDec) + '} seg' ; iOut2 := 256 * iCnt div 100 ; iOut := 256 - iOut2 ; iRed := iOut ; iGreen := iOut * 256 ; iBlue := iOut * 256 * 256 ; iColor := iBlue + iGreen + iRed ; Panel1.Color := iColor ; end; procedure TForm1.Button1Click(Sender: TObject); begin if Timer1.Enabled then begin Timer1.Enabled := false ; Button1.Caption := 'Re-Start It Again.' ; end else begin iCnt := 0 ; ProgressBar1.Position := 0 ; Timer1.Enabled := true ; Button1.Caption := 'Continue ...' ; end ; end; end.
Botons i missatges
MessageDlg
Displays a message, symbol, and selectable buttons
function MessageDlg ( const Message : string; DialogType : TMsgDlgType; Buttons : TMsgDlgButtons; HelpContext : Longint ) : Integer ;

url

Object-related events (from Object Inspector)
  • OnActivate
  • OnCanResize
  • OnClick
  • OnClose - let's close it, (user has accepted).
  • OnCloseQuery - ALT+F4 used : allow user to intercept it ! [Form Life-close]
  • OnCconstrainedResize
  • OnContextPopup
  • OnCreate() - inicialitzacions d'usuari [pere] [Form Life-create]
  • OnDblClick
  • OnDeactivate
  • OnDestroy() - finalitzacions d'usuari
  • OnDockDrop
  • OnDockOver
  • OnDragDrop
  • OnDragOver
  • OnEndDock
  • OnGetSiteInfo
  • OnHelp
  • OnHide
  • OnKeyDown
  • OnKeyPress
  • OnKeyUp
  • OnMouseDown
  • OnMouseMove
  • OnMouseUp
  • OnMouseWheel
  • OnMouseWheelDown
  • OnPaint
  • OnResize
  • OnShortCut
  • OnShow
  • OnStartDock
  • OnUnDock
TForm.Create(AOwner) ?
  • nil - specifies that no object owns the form and therefore a developer (you) is responsible for freeing the created form (by calling myForm.Free when you no longer need the form)
  • Self - specifies the object in which the method is called. If, for example, you are creating a new instance of a TMyForm form from inside a Button's OnClick handler (where this button is placed on a MainForm) - self refers to "MainForm". Thus, when the MainForm is freed - it will also free "MyForm".
  • Application - specifies a global TApplication type variable created when you run your application. "Application" encapsulates your application as well as providing many functions that occur in the background of the program.

url

Owner-draw ListBox

Use OnDrawItem to write a handler for drawing of the items in list boxes with the Style values lbOwnerDrawFixed, lbOwnerDrawVariable, or lbVirtualOwnerDraw.

OnDrawItem occurs when the list box needs to display an item.

OnDrawItem occurs only for owner-draw list boxes.

Set the ListBox1.Style prop. to lbOwnerDrawFixed :

procedure TTest.ListBox1DrawItem ( Control: TWinControl; Index: Integer; Rect: TRect; State: TOwnerDrawState ) ; begin With ( Control As TListBox ).Canvas Do Begin Case Index Of 0: Begin Font.Color := clBlue; Brush.Color := clYellow; End; 1: Begin Font.Color := clRed; Brush.Color := clLime; End; 2: Begin Font.Color := clGreen; Brush.Color := clFuchsia; End; End; FillRect(Rect); TextOut(Rect.Left, Rect.Top, ( Control As TListBox ).Items[Index]); End; end;
Imatges and GIFs

Natively, Delphi supports BMP, ICO, WMF and JPG images - these can be loaded into a graphic-compatible component (such as TImage) and used in an application.

url

Per fer servir un "Logo" :

  1. download the logo of your choice
  2. place a TImage component on a form
  3. use object Inspector to load the image into the component

url

Imatges dinàmiques
[LED_JPG.pas] var kVerde, kRojo, kAmarillo: TImage ; procedure TForm1.MyInit(Sender: TObject); begin kVerde.Picture.LoadFromFile ( 'led_verd.JPG' ) ; kRojo.Picture.LoadFromFile ( 'led_vermell.JPG' ) ; kAmarillo.Picture.LoadFromFile ( 'led_blanc.JPG' ) ; end; // TForm1.MyInit {somewhere else ... } Image2.Picture := kRojo.Picture ;
Graphics

To draw graphics in a Delphi application, you draw on an object's canvas, rather than directly on the object. The canvas is a property of the object, and is itself an object.

Delphi 6

Delphi 7 

 704.868.352   Borland_Delphi_V7.0_Enterprise_studio_1&2cd.ISO
          71   delphi.7.serial.txt [*]
     584.159   Teach-Yourself-Borland-Delphi-in-21-Days[ebook-html].zip
  15.100.391   Borland Delphi 7 Developer's Guide.pdf

 720.932.864 Delphi7.iso@500GB USB disk.

System requirements : (Borland Delphi 7 ? Edition)

Studio Architect Pentium 233 MHz XP, 2000, 98 64 MB RAM 520 MB HDD CD-ROM, SVGA, Mouse.
Studio Professional Pentium 233 MHz XP, 2000, 98 64 MB RAM 400 MB HDD CD-ROM, SVGA, Mouse.
Studio Enterprise Pentium 233 MHz XP, 2000, 98 64 MB RAM 450 MB HDD CD-ROM, SVGA, Mouse.
Personal Pentium 233 MHz XP, 2000, 98 32 MB RAM 160 MB HDD CD-ROM, SVGA, Mouse.

On a W95, this message comes up when starting Delphi32.exe :
A device attached to the system is not functioning.

And also
COREIDE70.BPL file is linked to missing export USER32.DLL:TrackMouseEvent

Delphi 7 Enterprise Suite setup launcher :

We can select :

  • Delphi 7
  • InterBase 6.5 Server
  • InterBase 6.5 Desktop Edition
  • Remote Debugger Server
  • ModelMaker 6.20
  • InstallShield Express

This message comes up :
Setup has found that a system registry setting for Just In Time debugging is set to another program (e:\VisualStudio\Common\MSDev98\bin\msdev.exe) See INSTALL.RTF

Features to be installed :

  • Program Files - highest performance rapid application development tool for W98, W2K and WXP.
  • Shared Files - files used by both Delphi and C++ Builder.
  • BDE - 32-bit high performance Borland Database Engine technology.
  • Database Desktop - database utility program
  • IntraWeb - framework and component set for building web applications in a true RAD manner.
  • Rave Visual Designer - Visual reporting Tool that can easily handle a wide variety of report formats.

SQL driver configuration :

  • MS Access : DAO 3.5 (MS Access 97) driver
  • Oracle : Oracle 8 driver
  • DB2 : DB2 UDB driver
  • Sybase : CT library driver
  • Informix : Informix 9 driver

Choose wheter you use VisiBroker/COBRA Support.

Install InterBase Client + Install/Upgrade to Data Access Components 2.7

InterBase 6.5 Server gets installed.

Java RTE 1.2.2-001 is installed.

VisiBroker (for C++) 4.5 gets installed.
OSAGENT_PORT := 14000
VBROKER_ADM := e:\Borland\adm
PATH larger that 512 chars !

Docu at file:///d:/Inprise/vbroker/vbcpp.html

Delphi Direct goes to Internet to get news !

Your Just-in-Time debugger is currently set to
'"c:\Program Files\Microsoft Visual Studio\Common\MSDev98\msdev.exe" -p %ld -e %ld'
In order for Just-in-Time Debugging and Distributed Debugging features to work correctly, it needs to be changed to:
'"c:\Program Files\Borland\Delphi7\bin\bordbg70.exe" -aeargs %ld %ld'.

Do you want to change this setting ?

Delphi 2005

Delphi's I've got

Top !
Machine Version
T42 delphi 7 Enterprise (Build 4.453) Registration Key: 2292737.
T42 VMware(GN) delphi 7 [cd1]
P4 delphi 7
"InterBase Guardian" service (Automatic) and "InterBase Server" service (Manual).
Kayak delphi 7 [cd1]

[cd1] CD "Borland Delpi v 7.0 Enterprise Studio 1 & 2.

704,868,352 Borland_Delphi_V7.0_Enterprise_studio_1&2cd.ISO @ VMware(gn) E:\Fonts_Delphi [u/k]

As it is an ISO, Daemon shall be used.

Llibres de Delphi que tinc

Teach Yourself Borland Delphi in 21 days - HTML : [C:\sebas\Delphi\Docu\7 days]
Delphi In A Nutshell - O'Reilly
Borland Delphi 7 Developer's Guide (CD Delphi 7) - 14,8 MB

Developer's Guide lessons

Top !

Examining a Delphi object

Page 4-2 : When you create a new project, the IDE displays a new form for you to customize. In the Code editor, the automatically generated unit declares a new class type for the form and includes the code that creates the new form instance. The generated code for a new Windows application looks like this:

unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs ; type TForm1 = class(TForm) { The type declaration of the form begins here } private { Private declarations } public { Public declarations } end; { The type declaration of the form ends here } var Form1: TForm1; implementation { Beginning of implementation part } {$R *.dfm} end.{ End of implementation part and unit}

Please, read What is "var Form1:TForm1" in Delphi Form's Unit Interface section?, amb preguntes com "Do I need the Form1 global variable?" ...

Suppose you add a button component to this form and write an OnClick event handler that changes the color of the form when the user clicks the button. This is the eventhandler code for the button's OnClick event:

procedure TForm1.Button1Click(Sender: TObject); begin Form1.Color := clGreen; end;

Changing the name of a component

You should always use the Object Inspector to change the name of a component.

Note that the code in the OnClick event handler for the button hasn't changed. Because you wrote the code, you have to update it yourself and correct any references to the form.

Scope and Qualifiers

Page 4-5 : 

 procedure TForm1.Button1Click(Sender: TObject);
 begin
  Color := clFuchsia ;
  Button1.Color := clLime ;
 end;

The first statement is equivalent to 

 Form1.Color := clFuchsia ;

You don't need to qualify Color with Form1 because the Button1Click method is part of TForm1; identifiers in the method body therefore fall within the scope of the TForm1 instance where the method is called. The second statement, in contrast, refers to the color of the button object (not of the form where the event handler is declared), so it requires qualification.

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Types of socket connections

On page 39-3 :

Socket connections can be divided into three basic types, which reflect how the connection was initiated and what the local socket is connected to. These are :

  • Client connections.
  • Listening connections.
  • Server connections.

Once the connection to a client socket is completed, the server connection is indistinguishable from a client connection. Both end points have the same capabilities and receive the same types of events. Only the listening connection is fundamentally different, as it has only a single endpoint.

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Sockets

The Internet palette page includes three socket components that allow your network application to form connections to other machines, and that allow you to read and write information over that connection. These are:

  • TcpServer
  • TcpClient
  • UdpSocket

Associated with each of these socket components are socket objects, which represent the endpoint of an actual socket connection. The socket components use the socket objects to encapsulate the socket server calls, so that your application does not need to be concerned with the details of establishing the connection or managing the socket messages. If you want to customize the details of the connections that the socket components make on your behalf, you can use the properties, events, and methods of the socket objects.

After completing the connection to a client or server socket, you can use the client or server socket object associated with your socket component to obtain information about the connection. Use the LocalHost and LocalPort properties to determine the address and port number used by the local client or server socket, or use the RemoteHost and RemotePort properties to determine the address and port number used by the remote client or server socket. Use the GetSocketAddr method to build a valid socket address based on the host name and port number. You can use the LookupPort method to look up the port number. Use the LookupProtocol method to look up the protocol number. Use the LookupHostName method to look up the host name based on the host machine's IP address. To view network traffic in and out of the socket, use the BytesSent and BytesReceived properties.

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Threads

For information on how to provide thread support to your application, see Chapter 13, "Writing multi-threaded applications", "Borland Delphi 7 for Windows - Developer's Guide" [\\t400\Delphi\Docu\DevGuide\Borland_Delphi_7_DeveloperS_Guide.pdf]

Thread objects do not allow you to control the security attributes or stack size of your threads. If you need to control these, you must use the BeginThread function. Even when using BeginThread, you can still benefit from some of the thread synchronization objects and methods described in "Coordinating threads" on page 13-7. For more information on using BeginThread, see the online Help.

On the other hand, because the thread shares the same process space with other threads, you can use the shared memory to communicate between threads.

Sometimes, however, you may want to use variables that are global to all the routines running in your thread, but not shared with other instances of the same thread class. You can do this by declaring thread-local variables. Make a variable thread-local by declaring it in a threadvar section.

Once you have implemented a thread class by giving it an Execute method, you can use it in your application to launch the code in the Execute method. To use a thread, first create an instance of the thread class. You can create a thread instance that starts running immediately, or you can create your thread in a suspended state so that it only begins when you call the Resume method. To create a thread so that it starts up immediately, set the constructor's CreateSuspended parameter to False. For example, the following line creates a thread and starts its execution:

SecondThread := TMyThread.Create(false) ; { create and run the thread }

Warning - Do not create too many threads in your application. The overhead in managing multiple threads can impact performance. The recommended limit is 16 threads per process on single processor systems. This limit assumes that most of those threads are waiting for external events.

function BeginThread ( SecurityAttributes : Pointer ; // nil is ok StackSize : LongWord ; // 0 is ok ThreadFunc : TThreadFunc ; // in : code Parameter : Pointer ; // in : data CreationFlags : LongWord ; // 0 is ok var ThreadId : LongWord // out : unique identifier ) : Integer ; // out : integer used by CloseHandle

Un uso para los threads : lanzar una tarea larga desde un botón. O poder lanzar una tarea "bloqueante" en paralelo con otra que no queremos que se detenga.

La funció BeginThread crida les primitives de windows. Crec que és més elegant, més senzill d'usar i més potent, utilitzar TThread.

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Let's start few Threads

The easiest way to create a multithreaded application in Delphi is to write a thread class that inherits from TThread
If you don't want to write a class, you can use BeginThread and EndThread. They are wrappers for the Win32 API calls CreateThread and ExitThread functions, but you must use Delphi's functions instead of the Win32 API directly. Deplhi keeps a global flag, IsMultiThread, which is True if your program calls BeginThread or starts a thread using TThread.

We can create threads using a simple Windows API function called CreateThread to bypass the TThread object altogether.

url

function CreateThread ( lpThreadAttributes : Pointer ; // (1) Address of thread security attributes [nil] dwStackSize : DWORD ; // (2) Thread stack size [0] - Initial size, in bytes lpStartAddress : TFNThreadStartRoutine ; // (3) Address of the thread function lpParameter : Pointer ; // (4) Input parameter for the thread dwCreationFlags : DWORD ; // (5) Creation flags [0] var lpThreadId : DWORD ) : // (6) ThreadID reference THandle ; stdcall ; // Function returns a handle to the thread, used by CloseHandle()

Sometimes, however, you may want to use variables that are global to all the routines running in your thread, but not shared with other instances of the same thread class. You can do this by declaring thread-local variables. Make a variable thread-local by declaring it in a threadvar section. For example,

threadvar x : integer;
declares an integer type variable that is private to each thread in the application, but global within each thread.

Book : Martin Harvey [T42:\\Delphi\MultiThreading\Internet\MartinHarvey]

sample

dwStackSize = the initial size of the stack, in bytes. The system rounds this value to the nearest page. If this parameter is zero, the new thread uses the default size for the executable.

CreateThread() @ MSDN2 sample.

The default size for the reserved and initially committed stack memory is specified in the executable file header. Thread or fiber creation fails if there is not enough memory to reserve or commit the number of bytes requested. The default stack size used by the linker is 1 MB. To specify a different default stack size for all threads and fibers, use the STACKSIZE statement in the module definition (.def) file. The linker rounds up the specified value to the nearest 4 bytes.

Thread Stack Size

Pere : caldria cridar GetLastError(), no et sembla ?

Pere's threads
type tSayHelloThread = class(TThread) private sayWhat : string ; sayHowMany : integer ; sayIdx : integer ; public constructor Create ( s : string; NumMsgs : integer ; IamIdx : integer ) ; protected procedure Execute ; override ; end; procedure tSayHelloThread.Execute ; var i, j, k, m : integer ; begin Form1.Say ( 'Inici del Thread [' + IntToStr(sayIdx) + '].' ) ; for i := 1 to sayHowMany do begin Form1.Say ( 'Soc el Thread '+IntToStr(sayIdx)+', texte <'+sayWhat+'> Bucle '+IntToStr(i)+'/'+IntToStr(sayHowMany) ) ; end ; end ; // tSayHelloThread.Execute constructor tSayHelloThread.Create ( s : string; NumMsgs : integer ; IamIdx : integer ) ; begin sayWhat := s ; sayHowMany := NumMsgs ; sayIdx := IamIdx ; inherited Create(false); end ; // tSayHelloThread.Create procedure TForm1.Button1Click ( Sender : TObject ) ; var t : tSayHelloThread ; i : integer ; begin for i := 1 to 10 do begin t := tSayHelloThread.Create ( Edit1.Text, 1000, i ) ; Say ( 'Thread {' + IntToStr(i) +'} created.' ) ; end ; end ; // Button1Click

T42:\\Delphi\Pere\HelloThread\

Sebas's threads
PtrMsgRecord = ^ TMsgRecord ; TMsgRecord = record ptrNext : PtrMsgRecord ; // dynamic chain link iThreadNumbering : integer ; // individual ID, own generated count. iThreadID : integer ; // BeginThread return value. lwThreadPointer : LongWord ; // BeginThread return value. iCommand : integer ; // 0 = stop, 1 = run iStatus : integer ; // 0 = stopped, 1 = running iNumConexions : integer ; // 0 = forever. szQMN : MQCHAR48 ; // queue manager name szHost : string ; // IP(port) of remote host szCanal : string ; // channel name used by MQ client bVerbose : boolean ; thConexio : THandle ; iCC : integer ; // Connect() results. iRC : integer ; msg : ShortString ; // . end ; MyNewItemPointer : PtrMsgRecord ; // dynamic item allocation new ( MyNewItemPointer ) ; // catch "On E : EOutOfMemory do" iThread := BeginThread ( nil, // SecurityAttributes lwStackSize, // StackSize Addr(Codi_De_Un_Thread), // ThreadFunc MyNewItemPointer, // Parameter 0, // CreationFlags lw_my_id ) ; // out : ThreadId MyNewItemPointer^.lwThreadPointer := lw_my_id ; MyNewItemPointer^.iThreadID := iThread ;

\\T400\MQ\Eines\AMQSCNXC_proves_Conexio_Client\IMI_Buscar_Max_Conexiones\thread_conexio.pas and \\T400\Delphi\MultiThreading\BuscarLimitThreads\*.pas

Threading links

Instalació

Question: the TClientSocket and TServerSocket components seem to be missing from my installation of Delphi 7

Solution:
You need to add the dclsockets package to the IDE. To do this go to Component | Install Packages | Add (/bin/dclsockets70.bpl).

OK - ja tinc "ClientSocket" i "ServerSocket" a la solapa de "Internet" ...

url

MQ at Delphi

Top !

La idea és primer passar el .H i el .LIB a una unit .PAS i poder accedir la DLL
El segon pas, construir un component Delphi que representi una qua MQ
Tercer, si cal, contruir una jerarquia de components que representin la comunicació amb MQ tipo JMS

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How to declare MQ vars
var qmn : MQCHAR48 ;
How to init MQ vars
var od : MQOD ; od := MQOD_DEFAULT ; // init Object Descriptor fields with default values.

MA7Q - MQI for Delphi, by Hans Hasert

There are two units in the package :

The SupportPac contains two files called 'MQI.PAS' and 'MQIC.PAS'. These are Pascal sources that should be placed somewhere in the Search Path of Delphi to be included in your Pascal program. The way to include it is like using any unit in Pascal :

uses MQI ; or uses MQIC ;

One of the implementations of the MQI (MQSeries Interface) on Windows is the 'C' interface. This interface is implemented by a dynamic link library that holds the calls a 'C' programmer can use to interface with MQ. Pascal implementations like Delphi can call external functions/procedures easily by declaring them as 'external' and 'C' versions by adding 'cdecl'. This is how the MQI units define the calls to the 'C' versions.

The MQI calls in the Pascal unit will resemble the ones described in the MQI 'C' interface, but bear in mind that the 'C' language uses pointers very explicitly and uses another method to determine the length of a string (which is marked by a #0 at the end and therefore 'C' strings are called 'null-terminated'). In Pascal the '@' operator is used to pass a pointer value, so you will see this operator regurarly when calling external procedures that adhere to the 'C' calling interface.

AMQAPI - MQ API Exerciser under Delphi

AMQAPI comença amb 3 solapes :

Queue Managers

Mostra una drop-down list amb els Queue Managers locals disponibles i una finestra amb el "Connected Queue Manager".
Les operacions disponibles son :

A la part de sota, com sempre, es mostra una finestra amb els resultats de les operacions, amb 3 camps : MQI (operacio), CC (condition code) i RC (reason code), as

MQI CC RC ------------------------------ MQCONN cc=2 rc=2059

Queues

Es mostra el "Connected Queue Manager" (necessari, escollit de abans), la "Selected Queue" i el "Selected Open Objects"
Les operacions disponibles son :

El CheckBox "Advanced Mode" permet l'accés a totes les opcions (que son moltes) del Open, Get, Put o Close.

A la part de sota, com sempre, es mostra una finestra amb els resultats de les operacions.

AMQAPI questions

MQ Delphi code

Pseudo URL [T42:\\Delphi\Pere\MQ]

MQAI Monitor

I ja està!! Es mostrarà el dibuix i es podrà posar al damunt el text que es vulgui.

Per últim, es pot canviar el dibuix dinàmicament, amb Image1.Picture.loadfromfile(filename)

Compte ! Nomes cal llegir del fitxer un cop, i es pot assignar molts cops :
[T42:\\Borland\Delphi7\Projects\Sebas\Leds_sobre_JPG\Led_JPG.pas]
[T42:\\Borland\Delphi7\Projects\Sebas\Port Paralel\port_paralel.pas]

[T42:\\Delphi\units\MQIC.PAS] - see "PDF and Administration Interface"

També "Support Pack" MA7Q = MQI for Delphi

SAG & Delphi & MQ
MQ multithread - clients esgotadors
T400:\\MQ\Eines\AMQSCNXC_proves_Conexio_Client\IMI_Buscar_Max_Conexiones\thread_conexio.pas
Other samples

Using MQIC with Delphi

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Unit's

Jo tinc un directori de "units" meves on hi poso els fonts i els resultats de la compilació. Cal dir-li al Delphi via Project | options | directories | Search Path on són.

Inicialització de la Unit :

unit holamon; interface implementation initialization writeln ('hola, mon!'); end. program hola; uses holamon; end.

Pot no haver objectes, per lo que no hi hauria "OnCreate()" !

My Unit's (Ago 08)

At T42:\\Delphi\Units\ tinc :

487 mem_sag.pas 1,277 mq_basic.pas 14.216 MQAI.pas 141,121 MQIC.pas 130,600 mqis.pas 2,943 ping.pas 710 sag_debug.pas 1.392 sag_timer.pas

Delphi 6 Tic-Tac-Toe WebService

url

Get Client ! here (?)

They also have

My top 10 reasons for upgrading to Delphi 2005

url

2004/10/12 - Borland Delphi 2005 Announced

Networking

Top !
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Delphi Client / Server
type ClientSocket1: TClientSocket ; //Connect to Server by button click procedure TTCPClient.btConnectClick ( Sender: TObject ) ; begin ClientSocket1.Host := edRemoteIP.Text; ClientSocket1.Port := strtoint(edRemotePort.Text); ClientSocket1.Active := True; end; //event handling and display connection state procedure TTCPClient.OnConnect ( Sender: TObject; Socket: TCustomWinSocket ) ; begin btSend.Enabled := True; btDisconnect.Enabled := True; btConnect.Enabled := False; mbReceiveData.Clear; Statusbar1.SimpleText := 'Connected to ' + ClientSocket1.Host; end; procedure TTCPClient.OnDisconnect ( Sender: TObject; Socket: TCustomWinSocket ) ; begin btSend.Enabled := False; btDisconnect.Enabled := False; btConnect.Enabled := True; Statusbar1.SimpleText := 'No Connection'; end; //Error handling procedure TTCPClient.OnError ( Sender: TObject; Socket: TCustomWinSocket; ErrorEvent: TErrorEvent; var ErrorCode: Integer ) ; begin ShowMessage ('Connection Error'); ClientSocket1.Active := False; btSend.Enabled := False; btDisconnect.Enabled := False; btConnect.Enabled := True; Statusbar1.SimpleText := 'No Connection'; end; //send test string by button click procedure TTCPClient.btSendClick ( Sender: TObject ) ; begin ClientSocket1.Socket.SendText (edSendData.Text); edSendData.Text := ''; end; //receive data handling procedure TTCPClient.OnRead ( Sender: TObject; Socket: TCustomWinSocket ) ; begin mbReceiveData.Text := mbReceiveData.Text + ClientSocket1.Socket.ReceiveText; end; //disconnect by button click procedure TTCPClient.btDisconnectClick ( Sender: TObject ) ; begin ClientSocket1.Active := False; end; type ServerSocket1: TServerSocket ; //start server listening by button click procedure TTCPServer.btListenClick(Sender: TObject); begin If edLocalPort.Text <> '' Then begin ServerSocket1.Port := strtoint(edLocalPort.Text); ServerSocket1.Open; end Else ShowMessage ('No local port!'); end; //event handling and display connection state procedure TTCPServer.OnListen(Sender: TObject; Socket: TCustomWinSocket); begin Statusbar1.SimpleText := 'Listening'; btSend.Enabled := False; btDisconnect.Enabled := False; btListen.Enabled := False; end; procedure TTCPServer.OnAccept(Sender: TObject; Socket: TCustomWinSocket); begin Statusbar1.SimpleText := 'Connected to ' + Socket.RemoteAddress; btSend.Enabled := True; btDisconnect.Enabled := True; end; procedure TTCPServer.OnClientDisconnect(Sender: TObject; Socket: TCustomWinSocket); begin Statusbar1.SimpleText := 'Listening'; ServerSocket1.Open; btSend.Enabled := False; btDisconnect.Enabled := False; end; //error handling procedure TTCPServer.OnClientError(Sender: TObject; Socket: TCustomWinSocket; ErrorEvent: TErrorEvent; var ErrorCode: Integer); begin ShowMessage ('Connection Error'); ErrorCode := 0; ServerSocket1.Close; btSend.Enabled := False; btDisconnect.Enabled := False; btListen.Enabled := True; Statusbar1.SimpleText := 'No Connection'; end; //send test string on button click procedure TTCPServer.btSendClick(Sender: TObject); begin ServerSocket1.Socket.Connections[0].SendText(edSendData.Text); edSendData.Text := ''; end; //receive data handling procedure TTCPServer.OnClientRead(Sender: TObject; Socket: TCustomWinSocket); begin mbReceiveData.Text := mbReceiveData.Text + Socket.ReceiveText; end; //end connection from server side by button click procedure TTCPServer.btDisconnectClick(Sender: TObject); begin ServerSocket1.Close; btListen.Enabled := True; btSend.Enabled := False; btDisconnect.Enabled := False; Statusbar1.SimpleText := 'No Connection'; end;
Send an Email from Delphi

Usar el Client SMTP de la màquina

begin emSubject := edit1.Text; emBody := memo1.Text; emTo:= edit2.text; emMailto := 'mailto:'+ emTo + '?subject=' + emSubject + '&body=' + emBody ; ShellExecute(Handle,'open',pChar(emMailto), nil, nil, SW_SHOWNORMAL) ; end;

There are many ways you can send an email directly from Delphi ; the most simple one is to use the ShellExecute API call to send an email using the default e-mail client software installed on a user's machine; this approach is ok, but you are unable to send attachments in this way.

url

Client SMTP

procedure TMailerForm.btnSendMailClick ( Sender: TObject ) ; begin StatusMemo.Clear ; // setup SMTP SMTP1.Host := edit1.Text ; SMTP1.Port := 25 ; Message1.From.Address := edit2.Text ; Message1.Recipients.EMailAddresses := edit3To.Text + ',' + edit4CC.Text ; Message1.Subject := edit5.Text ; Message1.Body.Text := Memo1.Text ; if FileExists ( editAttachment.Text ) then TIdAttachment.Create ( MailMessage.MessageParts, editAttachment.Text ) ; // send mail try try SMTP1.Connect ( 1000 ) ; SMTP1.Send ( Message1 ) ; except on E:Exception do Memo2.Lines.Insert ( 0, 'ERROR: ' + E.Message ) ; end; finally if SMTP1.Connected then SMTP1.Disconnect ; end ; (* btnSendMail Click *)

Sending Email Messages with Attachments using Delphi and Indy : \\sebas\Delphi\Email_Client\SendMail\MainUnit.pas

Have a look at this : A client that provides command line access to Lotus Notes email..

The Indy way : url; url;

MAPI.

send ARP packet : input IP, output MAC

You'll have to add this function to your unit to be able to send APR packages form your application.

Uses Winsock; Function SendARP ( DestIp: DWORD; srcIP: DWORD; pMacAddr: pointer; PhyAddrLen: Pointer ): DWORD ; stdcall; external 'iphlpapi.dll' ;

An example function that uses SendARP to get remote MAC address form IP address.

Function getRemoteMacAdress ( var address: String ): Boolean ; var dwRemoteIP: DWORD; PhyAddrLen: Longword; pMacAddr : array [0..1] of Longword; temp: array [0..5] of byte; I: Byte; begin Result := false ; dwremoteIP := inet_addr ( @address[1] ) ; if dwremoteIP <> 0 then begin PhyAddrLen := 6; if SendARP ( dwremoteIP, 0, @pMacAddr, @PhyAddrLen ) = NO_ERROR then begin if ( ( PhyAddrLen <> 0 ) and ( pMacAddr[0] <> 0 ) ) then begin Move ( pMacAddr, temp, 6 ) ; address := '' ; For I := 0 to 5 do address := address + inttohex (temp[i], 2) + '-' ; Delete ( address, Length ( address ), 1 ) ; Result := true ; end; end; end; end;

url based on MSDN

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Indy = Internet Direct

Indy uses blocking socket calls. ... Threading is almost always used with blocking sockets. ... Indy servers allocate a thread for each client connection. ... Plain text protocols can be debugged easily because they can be tested using a telnet session.

Introduction to Indy

URL :

Veure T42:c:\Archivos de programa\Borland\Delphi7\Source\Indy\idicmpclient.pas

Indy is a blocking library, and the calling thread's message queue is blocked while Indy is doing its work. You need to place a TIdAntiFreeze component onto your form or an additional worker thread with INDY Indy's synchronous operations internally call into TIdAntiFreeze periodicaly, which then calls Application.ProcessMessages().

Async programming. O mira't això també : Indy is Blocking. Blocking is not Evil.

Client "Zip Code Lookup"
unit ClientMain; interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls, IdAntiFreezeBase, IdAntiFreeze, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient; type TformMain = class(TForm) Client: TIdTCPClient; IdAntiFreeze1: TIdAntiFreeze; Panel1: TPanel; Panel2: TPanel; memoInput: TMemo; lboxResults: TListBox; Panel3: TPanel; Button1: TButton; Button2: TButton; Label1: TLabel; procedure Button2Click(Sender: TObject); procedure Button1Click(Sender: TObject); private public end; var formMain: TformMain; implementation {R *.DFM} procedure TformMain.Button2Click(Sender: TObject); begin memoInput.Clear; lboxResults.Clear; end; procedure TformMain.Button1Click(Sender: TObject); var i: integer; s: string; begin butnLookup.Enabled := true; try lboxResults.Clear; with Client do begin Connect; try lboxResults.Items.Add(ReadLn); for i := 0 to memoInput.Lines.Count - 1 do begin WriteLn('ZipCode ' + memoInput.Lines[i]); lboxResults.Items.Add(memoInput.Lines[i]); s := ReadLn; if s = '' then begin s := '-- No entry found for this zip code.'; end; lboxResults.Items.Add(s); lboxResults.Items.Add(''); end; WriteLn('Quit'); finally Disconnect; end; end; finally butnLookup.Enabled := true; end; end; end.

The only parts that are Indy specific are the Client component and the Button1Click method.

Client is a TIdTCPClient and is a component on the form. The following properties were altered from the default:

Button1Click is a method that is hooked to the OnClick event of Button1. When the button is clicked it executes this method.

The Indy portion of this method can be reduced to the following:

  1. Connect to Server ( Connect; )
  2. Read welcome message from the server.
  3. For each line the user entered in the TMemo:
    1. Send request to server ( WriteLn('ZipCode ' + memoInput.Lines[i]); )
    2. Read response from server ( s := ReadLn; )
  4. Send Quit command ( WriteLn('Quit'); )
  5. Disconnect ( Disconnect; )

Introduction to Indy

Server "Zip Code Lookup"
unit ServerMain; interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, IdBaseComponent, IdComponent, IdTCPServer; type TformMain = class(TForm) IdTCPServer1: TIdTCPServer; procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); procedure IdTCPServer1Connect(AThread: TIdPeerThread); procedure IdTCPServer1Execute(AThread: TIdPeerThread); private ZipCodeList: TStrings; public end; var formMain: TformMain; implementation {R *.DFM} procedure TformMain.IdTCPServer1Connect(AThread: TIdPeerThread); begin AThread.Connection.WriteLn('Indy Zip Code Server Ready.'); end; procedure TformMain.IdTCPServer1Execute(AThread: TIdPeerThread); var sCommand: string; begin with AThread.Connection do begin sCommand := ReadLn; if SameText(sCommand, 'QUIT') then begin Disconnect; end else if SameText(Copy(sCommand, 1, 8), 'ZipCode ') then begin WriteLn(ZipCodeList.Values[Copy(sCommand, 9, MaxInt)]); end; end; end; procedure TformMain.FormCreate(Sender: TObject); begin ZipCodeList := TStringList.Create; ZipCodeList.LoadFromFile(ExtractFilePath(Application.EXEName) + 'ZipCodes.dat'); end; procedure TformMain.FormDestroy(Sender: TObject); begin ZipCodeList.Free; end; end.

The only parts that are Indy specific are the IdTCPServer1 component, IdTCPServer1Connect method, and the IdTCPServer1Execute method.

IdTCPServer1 is a TIdTCPServer and is a component on the form. The following properties were altered from the default: * Active = True - Set the server to listen when the application is run. * DefaultPort = 6000 - An arbitrary number for this demo. This is the port the listener will listen on for incoming client requests.

The IdTCPServer1Execute method is hooked to the OnExecute event of the server. The OnExecute event is fired by the server after a client connection has been accepted. The OnExecute event is uniquely different from other events you may be familiar with. OnExecute is executed in the context of a thread. The thread the event is called from is passed in the AThread argument of the method. This is important as many OnExecute events may be executing at the same time. This was done with an event so that a server could be built without the requirement of building a new component.

The OnConnect is called after a connection has been accepted, and a thread created for it. In this server it is used to send the welcome message to the client. This could also be done in the OnExecute event if desired. The OnExecute event will be called repeatedly until the connection is disconnected or broken. This eliminates the need to check the connection and loop inside the event. IdTCPServer1Execute uses two basic Indy functions, ReadLn and WriteLn. ReadLn reads a line from the connection and WriteLn writes a line to the connection.

Introduction to Indy

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Ping

URL

uses Ping; ... const ADP_IP = '208.185.127.40'; (* http://delphi.about.com *) begin If Ping.Ping(ADP_IP) then ShowMessage ( 'About Delphi Programming reachable !' ) ; end;

I aquí és el codi : (requereix ICMP.DLL - mind access rights)

unit Ping; interface uses Windows, SysUtils, Classes; type TSunB = packed record s_b1, s_b2, s_b3, s_b4: byte; end; TSunW = packed record s_w1, s_w2: word; end; PIPAddr = ^TIPAddr; TIPAddr = record case integer of 0: (S_un_b: TSunB); 1: (S_un_w: TSunW); 2: (S_addr: longword); end; IPAddr = TIPAddr; function IcmpCreateFile : THandle; stdcall; external 'icmp.dll'; function IcmpCloseHandle (icmpHandle : THandle) : boolean; stdcall; external 'icmp.dll'; function IcmpSendEcho ( IcmpHandle : THandle ; DestinationAddress : IPAddr ; RequestData : pointer ; RequestSize : Smallint ; RequestOptions : pointer ; ReplyBuffer : pointer ; ReplySize : DWORD ; Timeout : DWORD ) : DWORD; stdcall; external 'icmp.dll'; function Ping( InetAddress : string ) : boolean; implementation uses WinSock; function Fetch ( var AInput : string ; const ADelim : string = ' ' ; const ADelete : Boolean = true ) : string; var iPos: Integer; begin if ADelim = #0 then begin // AnsiPos does not work with #0 iPos := Pos(ADelim, AInput); end else begin iPos := Pos(ADelim, AInput); end; if iPos = 0 then begin Result := AInput; if ADelete then begin AInput := ''; end; end else begin result := Copy(AInput, 1, iPos - 1); if ADelete then begin Delete(AInput, 1, iPos + Length(ADelim) - 1); end; end; end; procedure TranslateStringToTInAddr ( AIP: string; var AInAddr ) ; var phe: PHostEnt; pac: PChar; GInitData: TWSAData; begin WSAStartup($101, GInitData); try phe := GetHostByName(PChar(AIP)); if Assigned(phe) then begin pac := phe^.h_addr_list^; if Assigned(pac) then begin with TIPAddr(AInAddr).S_un_b do begin s_b1 := Byte(pac[0]); s_b2 := Byte(pac[1]); s_b3 := Byte(pac[2]); s_b4 := Byte(pac[3]); end; end else begin raise Exception.Create('Error getting IP from HostName'); end; end else begin raise Exception.Create('Error getting HostName'); end; except FillChar(AInAddr, SizeOf(AInAddr), #0); end; WSACleanup; end; function Ping ( InetAddress : string ) : boolean; var Handle : THandle; InAddr : IPAddr; DW : DWORD; rep : array[1..128] of byte; begin result := false; Handle := IcmpCreateFile ; if Handle = INVALID_HANDLE_VALUE then Exit; TranslateStringToTInAddr ( InetAddress, InAddr ) ; DW := IcmpSendEcho ( Handle, InAddr, nil, 0, nil, @rep, 128, 0 ) ; Result := (DW <> 0); IcmpCloseHandle ( Handle ) ; end; end.

DWORD IcmpSendEcho ( HANDLE IcmpHandle, IPAddr DestinationAddress, LPVOID RequestData, WORD RequestSize, PIP_OPTION_INFORMATION RequestOptions, LPVOID ReplyBuffer, DWORD ReplySize, DWORD Timeout ) ;

Return Values - Returns the number of ICMP_ECHO_REPLY structures stored in ReplyBuffer. The status of each reply is contained in the structure. If the return value is zero, call GetLastError for additional error information.

From here
Error code list

Ping using Indy

Indi Project, conceptes.

If you already installed Indy components, you may do it the short way : Put a IdICMPClient component in your form, fill in the property Host with the IP you want to ping, and write approximatively this :

var   Form1 : TForm1 ;   nbOk : integer ; implementation {$R *.dfm} procedure TForm1.FormCreate(Sender: TObject); begin   Timer1.Enabled := true ; end; procedure TForm1.Timer1Timer(Sender: TObject); var n : integer ; begin // resets the # of packets received   nbOk := 0 ; // 10 pings   for n := 1 to 10 do     IdICMPClient1.Ping() ; // % success display    Label1.Caption := FloatToStr ( nbOk * 10 ) + ' %' ; end; // ******************************************************************************************* // *** el codi seguent s'executa absolutament SINCRONE despres de "IdICMPClient1.Ping() ;" *** // ******************************************************************************************* procedure TForm1.IdIcmpClient1Reply(ASender: TComponent;   const AReplyStatus: TReplyStatus); begin // if one packet is received : nbOk is incremented   if AReplyStatus.BytesReceived > 0 then     inc(nbOk); end; procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction); begin   Timer1.Enabled := false ; end;

url

Atenció - si no hi ha conexió TCP/IP amb la xarxa, el codi anterior dona el següent error :

Project nom.exe raised exception class EIdSocketError with message 'Socket Error # 10065 No route to host'. Process stopped. Use Step or Run to continue.
Delphi Exception

Per agafar el control d'aquest incident, s'ha de codificar d'aquesta manera :

try idIcmpClient1.Ping(); except on e:Exception do debugmsg('Ping exception '+e.Message); end;

Petit problema : si fem correr el programa dins el IDE de Delphi, el Debugger captura l'excepció. Si no volem que sigui així, podem mirar Ignoring Exceptions with Delphi's Integrated Debugger o mirar "Tools | Debugger Options | Language Exceptions | Stop on Delphi Exceptions" .

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Get HTML

En Pere fa servir aquest codi :

program httpget ; { Pere Albert } uses classes, sysutils, wininet ; function LoadFromURL ( const fromURL : String ) : String ; var aURL : string ; hSession, hURL : hInternet ; Buffer : array [ 0..1023 ] of Byte ; BufferLength : longword ; Stream : TStringStream ; begin aURL := fromURL ; stream := TStringStream.Create ( '' ) ; Result := '' ; if ( Pos ( 'http://', LowerCase( aUrl ) ) = 0 ) then aURL := 'http://' + aURL ; hSession := InternetOpen ( 'PereApp:-)', INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0 ) ; try hURL := InternetOpenURL ( hSession, PChar( aURL ), nil, 0, INTERNET_FLAG_RELOAD, 0 ) ; try repeat InternetReadFile ( hURL, @Buffer, 1024, BufferLength ) ; Stream.WriteBuffer ( Buffer, BufferLength ) ; {$ifndef console} Application.ProcessMessages; {$endif} until ( BufferLength = 0 ) ; Result := Stream.DataString ; finally InternetCloseHandle ( hURL ) ; end; finally InternetCloseHandle ( hSession ) ; Stream.free ; end; end ; // function LoadFromURL begin writeln(loadFromURL(paramStr(1))); end.
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Get IP

Start Delphi and place one Button and two Edit boxes on a newly created Form. Add the GetIPFromHost function to the implementation part of your unit and assign the following code to the OnClick event handler of a button (below):

uses Winsock; function GetIPFromHost ( var HostName, IPaddr, WSAErr: string ) : Boolean; type Name = array[0..100] of Char; PName = ^Name; var HEnt: pHostEnt; HName: PName; WSAData: TWSAData; i: Integer; begin Result := False; if WSAStartup($0101, WSAData) <> 0 then begin WSAErr := 'Winsock is not responding."'; Exit; end; IPaddr := ''; New(HName); if GetHostName(HName^, SizeOf(Name)) = 0 then begin HostName := StrPas(HName^); HEnt := GetHostByName(HName^); for i := 0 to HEnt^.h_length - 1 do IPaddr := Concat(IPaddr, IntToStr(Ord(HEnt^.h_addr_list^[i])) + '.'); SetLength(IPaddr, Length(IPaddr) - 1); Result := True; end else begin case WSAGetLastError of WSANOTINITIALISED:WSAErr:='WSANotInitialised'; WSAENETDOWN :WSAErr:='WSAENetDown'; WSAEINPROGRESS :WSAErr:='WSAEInProgress'; end; end; Dispose(HName); WSACleanup; end; // GetIPFromHost procedure TForm1.Button1Click(Sender: TObject); var Host, IP, Err: string; begin if GetIPFromHost(Host, IP, Err) then begin Edit1.Text := Host; Edit2.Text := IP; end else MessageDlg(Err, mtError, [mbOk], 0); end;
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SNMP (Indy clients)

From Delphi Help :

Unit: IdSNMP.pas
IdSNMP.pas contains types and classes needed to implement a Simple Network Management Protocol (SNMP) client, as described in the Internet Standards document
RFC 1157 - A Simple Network Management Protocol [SNMP] (http://www.rfc-editor.org/rfc/rfc1157.txt)

Ports :

Simple SNMP client code sample :

.
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Menu bar

Per ajustar el darrer element a la dreta, fem :

procedure TForm1.FormCreate(Sender: TObject) ; var mii: TMenuItemInfo; MainMenu: hMenu; Buffer: array[0..79] of Char; begin MainMenu := Self.Menu.Handle; //GET Help Menu Item Info mii.cbSize := SizeOf(mii) ; mii.fMask := MIIM_TYPE; mii.dwTypeData := Buffer; mii.cch := SizeOf(Buffer) ; GetMenuItemInfo(MainMenu, HelpMenuItem.Command, false, mii) ; //SET Help Menu Item Info mii.fType := mii.fType or MFT_RIGHTJUSTIFY ; SetMenuItemInfo(MainMenu, HelpMenuItem.Command, false, mii) ; end;

url

Per amagar/mostrar el menu, podem fer :

// MainForm is the name of the form and MainMenu1: TMainMenu ; // Hide : MainForm.Menu := nil ; // Show : MainForm.Menu := MainMenu1 ;

url

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Children window

Volem que s'obri una finestra "fill" (pero independent ?) en polsar un boto.

La ventana principal del programa (Main) se distingue de cualquier otra por el valor de la propiedad FormStyle, que debe ser fsMDIForm, no pudiendo existir en el mismo proyecto más de una ventana con éste atributo.

Las fichas hijas se caracterizan por tener el valor fsMDIChild en la propiedad FormStyle, lo que asegura su correcta asociación con la ventana principal.

procedure TMainForm.About1Click(Sender: TObject); begin AboutBox := TAboutBox.Create(Self); try AboutBox.ShowModal; finally AboutBox.Free; end; end;

T42:C:\Archivos de programa\Borland\Delphi7\Demos\ActiveX\OleCtnrs\MDImain.pas

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Web Cam
type TMemoryStream = class(Classes.TMemoryStream); var MS : TMemoryStream; lSize : LongInt; pBuffer : ^Byte; begin MS := TMemoryStream.Create; bitmap1 := TBitmap.Create; try if VideoPortal1.PictureToMemory(0,24,0,lSize,'') = 1 then begin pBuffer := AllocMem(lSize); if VideoPortal1.PictureToMemory(0,24,integer(pBuffer),lSize,'') = 1 then begin MS.SetPointer(pBuffer,lSize); bitmap1.loadfromstream(MS); end; end; finally MS.Free; FreeMem(pBuffer); end;

From here

Get images

Mètode per cridar un executable i capturar-ne el output

En Pere indica que sempre es pot fer així ...

url, SSH from Synapse.

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Dynamic Form

Això és amb lo mínim que funciona :

var  NewLabel : TLabel ; begin   NewLabel := TLabel.Create(self) ;   NewLabel.Top := 99 ;   NewLabel.Caption := 'Abcdef ghijklm' ;   NewLabel.Parent := self ; (* conve posar : *)   NewLabel.Height := 19;   NewLabel.Width := 99;   NewLabel.Top := 19;   NewLabel.Left := 9;   NewLabel.Enabled := true;   NewLabel.Visible := true; end;
Monitor file contents change [4 Tania]
T42:\\VM\C:\Program Files\Borland\Delphi7\Projects\Sebas\BusquedaDeFicheros c:\Program Files\IBM\WebSphere MQ\errors\AMQERR01.LOG c:\Program Files\IBM\WebSphere MQ\Qmgrs\FEM49P01\errors\AMQERR01.LOG c:\Program Files\IBM\WebSphere MQ\Qmgrs\INDI\errors\AMQERR01.LOG c:\Program Files\IBM\WebSphere MQ\Qmgrs\MQCFGPRE\errors\AMQERR01.LOG c:\Program Files\IBM\WebSphere MQ\Qmgrs\MQPRE01\errors\AMQERR01.LOG
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My Tips & tricks

How to show a second form with an active title bar (url).

procedure TForm2.FormActivate(Sender: TObject); begin SendMessage(Application.MainForm.Handle, WM_NCACTIVATE, Boolean(True), 0); end;

How to show/hide the Menu (url).

procedure TForm1.Button2Click(Sender: TObject); begin if bMenuVisible then begin Button2.Caption := 'Mostrar Menu' ; Form1.Menu := nil ; end else begin Button2.Caption := 'Amagar Menu' ; Form1.Menu := MainMenu1 ; end; bMenuVisible := not bMenuVisible ; end ;

"ask" the Task Manager How Much Memory Is Your Delphi Program using (url).

uses PsAPI ... // current memory size of the current process in bytes function CurrentMemoryUsage: Cardinal; var pmc: TProcessMemoryCounters; begin pmc.cb := SizeOf(pmc) ; if GetProcessMemoryInfo(GetCurrentProcess, @pmc, SizeOf(pmc)) then Result := pmc.WorkingSetSize else RaiseLastOSError; end; To display the memory usage in KB, use: ShowMessage( FormatFloat( 'Memory used: ,.# K', CurrentMemoryUsage / 1024 ) ) ;

URLs : DelphiTips.

Pending

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Millores (Maig 2010)

Dubtes

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Delphi links

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Best place : Delphi.About.com [Zarko Gajic]. Forum
Delphi Basics [****], as First Program.
History of Delphi Strings
Arqueologia

Retrieving volume's (disk / drive) serial number : URL

A guide to developing Delphi programs in Windows API (without the use of the VCL) : URL

Windows User Interface (MSDN).

Delphi tips - Windows OS and API : URL, Scalabium.

An introduction to hook procedures : URL

Codificació d' Excepcions
Colin Wilson's site (D3 & 4, D5, D6, D7, 2005 & 2006)
Custom Event log from here [t42:\\Delphi\Magazines\TheDelphiMagazine\*.zip - 50 MB]
Service Application in Delphi
Learn to program Delphi part one, part two.

Curs bàsic.

See Delphi section
Delphi 4.0 shareware Programming Tools - see SVCOM.
DSP = Delphi Super Page ! And search engine ... Delphi Super Page mirror

Nice links

A Service in C !
Dr Bob's Delphi index
Source codes
Win32 at Borland
Tutorial [*****]
Tutorial (private)
Delphi tutorial
Tips and FAQs , as IP @, MAC @, etc.
Lots of questions
Delphi Graphics Info and Links. Algorithms. Tons of Links !
Delphi GDI drawing (intro), from Homepage. They say :
Borland Delphi is a probably the best if not one of the most impressive and the richest programming environment known to mankind and Delphi 2005 absolutely has no comparison.
Cursos :
  • Curso de creación de componentes en Delphi.
  • Learning Object Oriented Programming with Delphi - TOC [Zarko Gajic, 14 parts, 27 capítols]
Delphi and Kylix programming zone.
Delphi and Kylix Help, Tutorials, etc. New ?
Kylix tips Torry's Delphi
The Unofficial Newsletter of Delphi Users ... goes back as far as 1997 !
Read how to record and playback sound in a Delphi application
See Task Desk - Task Manager on desktop (Delphi + WinAPI).

Build your own Start menu

TP links page : url

EFG's

Picture Motion - double buffering

Restoring a drawing

Central Iowa Delphi Users Group (nice looking !)

Using The Windows API In Delphi

LaunchPad : windir(), currdir(), ShellExecute(), Displaying Icons, Launching Files, Creating Controls At Runtime
Samples from Delphi.About.Com : {Zarko Gajic}
Sokoban (with source)
Boletin (num 50) interesante
Moving from VB to Delphi 2.0
How to use Chilkat ActiveX components in Delphi.
Lots of tips (256)
Resources
Few Prog Samples
Chapter 4 for Delphi Unleashed 1.0: 16 Bit
Prevent memory leaks : here

url, url.

"The Big Brother" Delphi code toolkit : URL, url,

  • hiding from the task list
  • disabling task-switch
  • removing from the TaskBar
  • disabling shut down
  • dWinLock & dGina.dll + "Storing dGina.dll inside the exe"
WikiDelphi 2010 & Anders Hejlsberg

2011 : homepage, XE2 : vaja preus !

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