PageStatePersister.Save Method ()

 

Overridden by derived classes to serialize persisted state information when a Page object is unloaded from memory.

Namespace:   System.Web.UI
Assembly:  System.Web (in System.Web.dll)

Public MustOverride Sub Save

Classes that derive from the PageStatePersister class implement the Save method to persist the contents of the ViewState and ControlState properties to a persistence medium.

The following code example demonstrates how a class that derives from the PageStatePersister class implements the Save method to persist view state to a persistence medium. The StreamPageStatePersister uses an IStateFormatter object to serialize the contents of the ViewState property and ControlState property. This code example is part of a larger example provided for the PageStatePersister class.

'
' Persist any ViewState and ControlState.
'
Public Overrides Sub Save()

    If Not (ViewState Is Nothing) OrElse Not (ControlState Is Nothing) Then
        If Not (Page.Session Is Nothing) Then

            Dim stateStream As Stream
            stateStream = GetSecureStream()

            ' Write a state string, using the StateFormatter.
            Dim writer As New StreamWriter(stateStream)

            Dim formatter As IStateFormatter
            formatter = Me.StateFormatter

            Dim statePair As New Pair(ViewState, ControlState)

            Dim serializedState As String
            serializedState = formatter.Serialize(statePair)

            writer.Write(serializedState)
            writer.Close()
            stateStream.Close()
        Else
            Throw New InvalidOperationException("Session needed for StreamPageStatePersister.")
        End If
    End If
End Sub 'Save

.NET Framework
Available since 2.0
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