请问如何知道窗体最小化事件!!!(5分)

如题！！！望指教！！！！

procedure WMSysCommand(var Message: TWMSysCommand); message WM_SYSCOMMAND;


procedure TForm1.WMSysCommand(var Message: TWMSysCommand);
begin
inherited;
if Message.CmdType and $FFF0 = SC_MINIMIZE then
begin
ShowMessage('');
end;
end;

接受答案了.