Foreign control exception
when i create an usercontrol , and implement one interface, then i removet System.Web.UI.UserControl ,
Oh Stanage eror was be report, Seek for... then i find beacuse the base class was be reomve by me unwarily.
新建了一个user control 让它继承于 某个接口。结果也把
System.Web.UI.UserControl 给删掉了。
恢复这个就正常了