如何使用动态添加的Control子类访问Control.ViewState？

We have created a control that needs to persist data via the ViewState property of the Control class. Our class subclasses control strictly to get access to the ViewState property (it's protected on the Page object). We are adding the control to Page.Controls in OnInit, and then attempt to set the ViewState property in OnPreLoad.We have created a control that needs to persist