# aardio 范例: 监听任务栏消息 - 检测是否有全屏窗口



```aardio
import win.ui;
/*DSG{{*/
var winform = win.form(text="监听任务栏消息 - 检测是否有全屏窗口";right=759;bottom=469)
winform.add(
edit={cls="edit";left=32;top=22;right=734;bottom=431;edge=1;multiline=1;z=1}
)
/*}}*/

//相关范例: https://www.aardio.com/zh-cn/docs/examples/Automation/Windows/shellhook.html
import win.appBar;
win.appBar.regist(winform,function(code,param){
	if(code == 2/*_ABN_FULLSCREENAPP*/){
		//param 为当前是否有全屏窗口
		winform.edit.print("全屏",!!param);
	}
}) 

winform.show();
win.loopMessage();

```