核心教程第十一课-多线程在软件开发中的应用(2)

线程的控制

 

 procedure TNumThread.Execute;

var

  i:Integer;

begin

  FreeOnTerminate:=True;//线程结束立刻释放线程对象

  For i:=0 to 5000000 do

  begin

    if Terminated then Break;//强行终止线程的时候为真

    Inc(Answer,Round(Abs(Sin(Sqrt(i*87)))));

    Synchronize(GetAnswer);

  end;

end;

implementation

uses Unit2;

{$R *.dfm}

var

  NumThread:TNumThread;

procedure TForm1.btn1Click(Sender: TObject);

begin

  NumThread:=TNumThread.Create(False); //这个false，意思是是否延时运行？

end;

//线程挂起

procedure TForm1.btngqClick(Sender: TObject);

begin

  //判断线程是否存在

  if Assigned(NumThread) then

  NumThread.Suspend;

end;

//线程唤醒

procedure TForm1.btnhxClick(Sender: TObject);

begin

  if Assigned(NumThread) then

  NumThread.Resume;

end;

//线程终止

procedure TForm1.btnjsClick(Sender: TObject);

begin

  if Assigned(NumThread) then

  NumThread.Terminate;

end;