tmsethread

[Properties (by Name)] [Methods (by Name)]

Runs a method or a global function in a separate thread, so that a long operation does not block the application while it runs

Declaration

Source position: msethread.pas line 42

Inheritance

Description

Runs a method or a global function in a separate thread, so that a long operation does not block the application while it runs. The following example starts a three second simulated operation in a thread while a paint box blinks to show that the user interface stays responsive, and properly terminates the thread when the form is destroyed.

uses
  main_mfm;

{ ttestthreadcontainer }

destructor ttestthreadcontainer.Destroy;
begin
  if FThread <> nil then
  begin
    FThread.Terminate;
    application.WaitForThread(FThread);
    FThread.Destroy;
  end;
  inherited;
end;

procedure ttestthreadcontainer.Run;
begin
  FThread := tmsethread.Create(@Execute);
end;

function ttestthreadcontainer.Execute(thread: tmsethread): integer;
begin
  Sleep(3000);
  mainfo.tmWait.Enabled := FALSE;
  ShowMessage('Operation completed.');
  result := 0;
end;

{ tmainfo }

procedure tmainfo.ButtonExecute(const sender: TObject);
begin
  tmWait.Enabled := TRUE;
  FThreadContainer.Run;
end;

procedure tmainfo.FormCreate(const sender: TObject);
begin
  FThreadContainer := ttestthreadcontainer.Create();
  FBlink := FALSE;
end;

procedure tmainfo.TimerExecute(const sender: TObject);
begin
  pbWait.Invalidate;
  FBlink := not FBlink;
end;

procedure tmainfo.PaintBoxPaint(const sender: twidget; const acanvas: tcanvas);
begin
  if FBlink then
    acanvas.FillRect(MakeRect(0, 0, sender.bounds_cx, sender.bounds_cy), CL_BLUE);
end;

procedure tmainfo.FormDestroy(const sender: TObject);
begin
  FThreadContainer.Free;
end;