Control state is an object comprised of critical view state data that Web server controls need to function, and is contained in a separate object from normal view state information. Control state data is not affected when view state is disabled at the Page level, but requires extra implementation steps to use. For more information on using the ViewState property and control state when developing controls, see Developing Custom ASP.NET Server Controls.

The following code example demonstrates how a class that derives from the PageStatePersister class initializes the ControlState property. In this example, the ControlState property has been assigned to the Second field of a Pair object, and serialized using the ObjectStateFormatter class. When the Load method is called, the ObjectStateFormatter class is used to deserialize view state and control state information, and the ControlState property is initialized from the resulting Pair object's Second field. This code example is part of a larger example provided for the PageStatePersister class.

'
' Load ViewState and ControlState.
'
Public Overrides Sub Load()

    Dim stateStream As Stream
    stateStream = GetSecureStream()

    ' Read the state string, using the StateFormatter.
    Dim reader As New StreamReader(stateStream)

    Dim serializedStatePair As String
    serializedStatePair = reader.ReadToEnd
    Dim statePair As Pair

    Dim formatter As IStateFormatter
    formatter = Me.StateFormatter

    ' Deserilize returns the Pair object that is serialized in
    ' the Save method.      
    statePair = CType(formatter.Deserialize(serializedStatePair), Pair)

    ViewState = statePair.First
    ControlState = statePair.Second
    reader.Close()
    stateStream.Close()
End Sub ' Load

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

.NET Framework

Reference