我是截取鼠标移动消息,放一个ApplicationEvents
procedure Tfrm_main.ApplicationEventsMessage(var Msg: tagMSG;var Handled: Boolean);
var
p:TPoint;
begin
if message=WM_MOUSEMOVE then
begin
p:=p_back.ScreenToClient(pt);
p_history.Visible:=((p.X<=25) and (p.Y<=25) and (p.X>=0) and (p.Y>=0));
end;
end;