procedure TForm1.Button4Click(Sender: TObject);
begin
   COM_RUN:= TEvent.Create(nil,true,false,'');
   COM_RUN.SetEvent;
    BR:=Thread_BR.Create(false);                            //在这里建立起线程
    WR:=Thread_BW.Create(false);                         
    WW:=Thread_WW.Create(false);
end;procedure TForm1.Button1Click(Sender: TObject);
begin
    inc(diaoyong_BR);                                       //随着按键的次数增加,在线程
end;                                                        //的循环里刷新memo控件的显示procedure Thread_BR.Execute;                                //执行线程
begin
    while(RUN_COUNT_BR<diaoyong_BR) do begin
      inc(RUN_COUNT_BR);                                       
      while(form1.COM_RUN.WaitFor(100)<>wrSignaled) do
      begin
      end;
      if (Terminated) then exit;
      Form1.COM_RUN.ResetEvent;
      form1.Memo1.Lines.Append('BR正在进行第 '+inttostr(RUN_COUNT_BR) +' 次');
      form1.delay(1000);
      form1.Memo1.Lines.Append('BR结束');
      Form1.COM_RUN.SetEvent();
   end;
end;                 问题来了,为什么先按下button4,然后我按下button1之后, memo1没有能够显示 'BR正在进行第1次'的信息.而是在先按了button1之后再按button4才显示,这是什么道理?