获得窗口句柄

procedure TForm1.Timer1Timer(Sender: TObject);
var
  handle,hchild1,hchild2:THandle;
  point:TPoint;
  temp:array[0..255] of char;
begin

://取得当前鼠标的位置
  GetCursorPos(point);
//取得当前鼠标所在窗体的句柄

handle:=WindowFromPoint(point);
  GetClassName(handle,temp,256);
  //#32770是对话框的类名，QQ窗体的类名就是#32770

  if temp='#32770' then

  begin

  //为了确保是QQ登陆窗体，再检查有没有“登陆”和“注册向导”两个按扭
    hchild1:=FindWindowEx(handle,0,'Button','登录');
    hchild2:=FindWindowEx(handle,0,'Button','注册向导');
    if (hchild1<>0) and (hchild2<>0) then
       SendMessage(handle,WM_CLOSE,0,0);
  end;
end;