unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, system.SyncObjs;
type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
Memo1: TMemo;
CheckBox1: TCheckBox;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure CheckBox1Click(Sender: TObject);
private
public
{ Public declarations }
end;
TMyThread = class(TThread)
protected
procedure Execute; override;
end;
var
Form1: TForm1;
AEvent: TEvent;
MyThread: TMyThread;
implementation
{$R *.dfm}
procedure Log(Msg: string);
begin
TThread.Synchronize(nil, procedure begin
Form1.Memo1.Lines.Add(Msg);
end);
end;
{ TMyThread }
procedure TMyThread.Execute;
begin
while not Terminated do
begin
AEvent.Acquire;
Log(DateTimeToStr(Now));
TThread.Sleep();
end;
Log('Exit');
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
AEvent.SetEvent;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
AEvent.ResetEvent;
end;
procedure TForm1.CheckBox1Click(Sender: TObject);
begin
MyThread.Terminate;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
Memo1.Clear;
AEvent := TEvent.Create(nil, False, False, '');
MyThread := TMyThread.Create(False);
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
if not MyThread.Finished then
begin
//确保线程正常退出
MyThread.Terminate;
AEvent.SetEvent;
MyThread.WaitFor;
end;
MyThread.Free;
AEvent.Free;
end;
end.
AEvent := TEvent.Create(nil, False, False, '');
第一个False, 线程是否可以执行一次. 如何为True,相当于 do while, 如果为 False , 相当于 while .
第二个False, 相当于线程是否可以直接运行，不需要SetEvent. 如果为 True , 则必须调用 SetEvent 后，线程才能运行。也就是线程启动后就被阻塞住。
当两个同时为 False 时， 就可以实现类似 PulseOneEvent 的功能。
TLightweightEvent 和 TEvent 基本上是一样的，它是从 .NET中的 System.Threading.ManualResetEventSlim 学来的。对于多核，短时间间隔效率更好，可参考 MSDN 。