外部组件异常

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