三天不写代码就手生! 把测试代码记录下来。
unit Unit1; interfaceuses Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls; type TForm1 = class(TForm) Button1: TButton; Button2: TButton; Button3: TButton; Button4: TButton; Memo1: TMemo; CheckBox1: TCheckBox; CheckBox2: TCheckBox; procedure FormCreate(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); private FFlag: Boolean; public{ Public declarations }end; var Form1: TForm1; implementation{$R *.dfm}procedure Log(Msg: string); begin TThread.Synchronize(nil, procedurebegin Form1.Memo1.Lines.Add(Msg); end); end; procedure TForm1.Button1Click(Sender: TObject); begin//错误if System.MonitorTryEnter(Form1) thenbegin System.MonitorEnter(Form1); System.MonitorPulseAll(Form1); System.MonitorExit(Form1); endelse Log('????'); end; procedure TForm1.Button2Click(Sender: TObject); begin//正确 System.MonitorPulseAll(Form1); end; procedure TForm1.FormCreate(Sender: TObject); var AThread: TThread; begin FFlag := True; TThread.CreateAnonymousThread(procedurebeginwhile True dobeginif Form1.CheckBox2.Checked then Exit; if Form1.FFlag thenbegin System.MonitorEnter(Form1); //必须 Log('Thread1 Enter'); System.MonitorWait(Form1, INFINITE); Log('Thread1 WaitFor'); System.MonitorExit(Form1); //必须 Log('Thread1 Exit'); end; Log(DateTimeToStr(Now)); TThread.Sleep(100); end; Log('Thread Exit'); end).Start; TThread.CreateAnonymousThread(procedurebeginwhile True dobeginif Form1.CheckBox2.Checked then Exit; if Form1.FFlag thenbegin System.MonitorEnter(Form1); Log('Thread2 Enter'); System.MonitorWait(Form1, INFINITE); Log('Thread2 WaitFor'); System.MonitorExit(Form1); Log('Thread2 Exit'); end; Log(DateTimeToStr(Now)); TThread.Sleep(100); end; Log('Thread Exit'); end).Start; end; end.
注意事项:
1. 三个方法必须一块使用,不能只写 System.MonitorWait(Form1, INFINITE);
System.MonitorEnter(Form1); //必须
Log('Thread1 Enter');
System.MonitorWait(Form1, INFINITE);
Log('Thread1 WaitFor');
System.MonitorExit(Form1); //必须
Log('Thread1 Exit');
2. System.MonitorPulseAll(Form1) 即可。不要这样写
System.MonitorEnter(Form1);
System.MonitorPulseAll(Form1);
System.MonitorExit(Form1);