When control state is saved, a string object is returned to the client as a variable that is stored in an HTML HIDDEN element. Override this method to extract the state information to use in your control.
Control state is intended for small amounts of critical data, such as a page index or a keyword. Using control state for large amounts of data can adversely affect page performance. For more information, see ASP.NET State Management Overview.
The following code example overrides the SaveControlState method in a custom ASP.NET control. When this method is invoked, it determines whether the internal property currentIndex is set to a non-default value and, if so, saves the value to control state.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2