Page.RequiresControlState Method (Control)
Determines whether the specified Control object is registered to participate in control state management.
Assembly: System.Web (in System.Web.dll)
Control state is an object composed of critical view-state data that Web server controls need to function; it is contained in a separate object from normal view state.
Custom controls using control state must call the RegisterRequiresControlState method before saving control state. Use the method to check for controls that are registered with the page as requiring control state.
Available since 2.0