Saves any server control state changes that have occurred since the time the page was posted back to the server.
Assembly: System.Web (in System.Web.dll)
Use the method to save state information required for the operation of a specific control. This control-state data is stored separately from the control's view-state data.Notes to Inheritors
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 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 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.