how to run code in background

[rcmz]

hi,

How can I run code in background?

In Delphi I uses TBackgroundWorker

Any ideas?

TIA
rcmz

[cdbc]

Hi
I think, underneath "TBackgroundWorker" is a thread, sooo use a thread 
Regards Benny

[Zvoni]

TThread?

[AlanTheBeast]

TThread?

Without objections, I would do:

Code: Pascal  [Select][+][-]

1. Function Achunkofrealpascal (p:pointer):ptrint;
2. VAR
3.    z:somerecord;
4. BEGIN
5.    z := somerecord(p^);
6.    While not z.Shutdown do
7.       begin
8.          stuff;
9.          sleep(z.SleepPeriod);
10.       end;
11.    exit(0);
12. END;
13.  
14. //somewhere in main:
15.   With BlockOfData do
16.     begin
17.        Shutdown := false;
18.        SleepPeriod := 100;  //ms
19.        Otherstuff := ...
20.    end;
21.   TID := BeginThread(@Achunkofrealpascal, @Blockofdata);

Notes: use flags or data in the referenced record to send signals into/out of the background thread.

You can kill the thread using TID as a reference, or (in the case above) by setting Shutdown to true.

[Jiyahana]

You can use TThread specifically by creating a descendant of the TThread class. Implement the code that needs to run in the background within the execute method of the TThread descendant.

Example.

uses
  System.Classes;

type
  TMyBackgroundThread = class(TThread)
  protected
    procedure Execute; override;
  end;

procedure TMyBackgroundThread.Execute;
begin
  // Perform the background operations here
  // Ensure synchronization if accessing UI elements
end;

Instantiate and start the background thread where needed in your Delphi application.

var
  MyThread: TMyBackgroundThread;
begin
  MyThread := TMyBackgroundThread.Create(True); // Create suspended
  MyThread.FreeOnTerminate := True; // Auto-free thread when done
  MyThread.Start; // Start the background thread
end;

I hope example will help.

[Thaddy]

Not really.
Much easier are the options possible for TThread,ExecuteInThread()

[rcmz]

Thx,

I will try it.

[KodeZwerg]

If its something where you not need to take much care about ...

Code: Pascal  [Select][+][-]

1. procedure ThreadProc;
2. begin
3.   // all code that needs to run threaded belong in here
4.   Sleep(5000);
5.   Form1.Button1.Enabled := True;
6. end;
7.  
8. procedure TForm1.Button1Click(Sender: TObject);
9. var
10.   AProc: TProcedure;
11. begin
12.   Button1.Enabled := False;
13.   AProc := @ThreadProc;
14.   TThread.CreateAnonymousThread(AProc).Start;
15. end;

Have in mind, code will run to its endphase even if you closed your process somehow.

[Thaddy]

I would still also save the result of the not so anonymous thread, since it returns a valid TThread that can be used later when needed. Comes to mind TThread.CheckTerminated.

[Zvoni]

I would still also save the result of the not so anonymous thread, since it returns a valid TThread that can be used later when needed. Comes to mind TThread.CheckTerminated.

Nevermind WaitFor and OnTerminated