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copied!<p>Obviously, somewhere there has to be a reference to the instantiated thread. But I can relate to your wish: you want a always-done-never-care solution.</p> <p>I suggest you manage the thread's existence by a separate ThreadController class:</p> <pre><code>unit Unit2; interface uses Classes, SysUtils, Forms, Windows, Messages; type TMyThreadProgressEvent = procedure(Value: Integer; Proceed: Boolean) of object; procedure RunMyThread(StartValue: Integer; OnProgress: TMyThreadProgressEvent); implementation type TMyThread = class(TThread) private FException: Exception; FOnProgress: TMyThreadProgressEvent; FProceed: Boolean; FValue: Integer; procedure DoProgress; procedure HandleException; procedure ShowException; protected procedure Execute; override; end; TMyThreadController = class(TObject) private FThreads: TList; procedure StartThread(StartValue: Integer; OnProgress: TMyThreadProgressEvent); procedure ThreadTerminate(Sender: TObject); public constructor Create; destructor Destroy; override; end; var FMyThreadController: TMyThreadController; function MyThreadController: TMyThreadController; begin if not Assigned(FMyThreadController) then FMyThreadController := TMyThreadController.Create; Result := FMyThreadController end; procedure RunMyThread(StartValue: Integer; OnProgress: TMyThreadProgressEvent); begin MyThreadController.StartThread(StartValue, OnProgress); end; { TMyThreadController } constructor TMyThreadController.Create; begin inherited; FThreads := TList.Create; end; destructor TMyThreadController.Destroy; var Thread: TThread; begin while FThreads.Count > 0 do begin Thread := FThreads[0]; //Save reference because Terminate indirectly //extracts the list entry in OnTerminate! Thread.Terminate; //Indirectly decreases FThreads.Count Thread.Free; end; FThreads.Free; inherited Destroy; end; procedure TMyThreadController.StartThread(StartValue: Integer; OnProgress: TMyThreadProgressEvent); var Thread: TMyThread; begin Thread := TMyThread.Create(True); FThreads.Add(Thread); //Add to list before a call to Resume because once //resumed, the thread might be gone already! Thread.FValue := StartValue; Thread.FOnProgress := OnProgress; Thread.OnTerminate := ThreadTerminate; Thread.Resume; end; procedure TMyThreadController.ThreadTerminate(Sender: TObject); begin FThreads.Extract(Sender); end; { TMyThread } procedure TMyThread.DoProgress; begin if (not Application.Terminated) and Assigned(FOnProgress) then FOnProgress(FValue, FProceed); end; procedure TMyThread.Execute; begin try FProceed := True; while (not Terminated) and (not Application.Terminated) and FProceed and (FValue < 20) do begin Synchronize(DoProgress); if not FProceed then Break; Inc(FValue); Sleep(2000); end; //In case of normal execution ending, the thread may free itself. Otherwise, //the thread controller object frees the thread. if not Terminated then FreeOnTerminate := True; except HandleException; end; end; procedure TMyThread.HandleException; begin FException := Exception(ExceptObject); try if not (FException is EAbort) then Synchronize(ShowException); finally FException := nil; end; end; procedure TMyThread.ShowException; begin if GetCapture <> 0 then SendMessage(GetCapture, WM_CANCELMODE, 0, 0); if (FException is Exception) and (not Application.Terminated) then Application.ShowException(FException) else SysUtils.ShowException(FException, nil); end; initialization finalization FreeAndNil(FMyThreadController); end. </code></pre> <p>To run this sample thread which counts from 5 to 19 in 2 second intervals and provides feedback and an opportunity to a premature termination, call from the main thread:</p> <pre><code>type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); private procedure MyThreadProgress(Value: Integer; Proceed: Boolean); end; ... procedure TForm1.Button1Click(Sender: TObject); begin RunMyThread(5, MyThreadProgress); end; procedure TForm1.MyThreadProgress(Value: Integer; Proceed: Boolean); begin Caption := IntToStr(Value); end; </code></pre> <p>This thread automatically kills itself on either thread's or application's termination.</p> <p>Maybe this unit is a little overkill for your situation because it is capable of handling multiple threads (of the same type), but I think it answers your question. Adjust to your liking.</p> <p><sup>Partial origin of this answer: <a href="http://www.nldelphi.com/forum/showthread.php?t=24450" rel="nofollow">NLDelphi.com</a>.</sup></p>

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