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UserControl.LoadViewState Method

Restores the view-state information from a previous user control request that was saved by the SaveViewState method.

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

'Declaration
Protected Overrides Sub LoadViewState ( _
	savedState As Object _
)

Parameters

savedState
Type: System.Object

An Object that represents the user control state to be restored.

This method is used primarily by the .NET Framework infrastructure and is not intended to be used directly from your code. However, control developers can override this method to specify how a custom server control restores its view state. For more information, see ASP.NET State Management Overview.

You can load a view-state value into a field so that you do not have to retrieve it from the Control.ViewState property later. You can also insert the value into the ViewState property just before calling SaveViewState , which is an effective way to make a field persist across round trips to the server.

The following example demonstrates a user control that manages its view state using the LoadViewState and SaveViewState methods.

Public Property UserText() As String 

        Get 
            Return CStr(ViewState("usertext"))
        End Get 
        Set(ByVal value As String)
            ViewState("usertext") = value
        End Set 

    End Property 

    Public Property PasswordText() As String 

        Get 
            Return CStr(ViewState("passwordtext"))
        End Get 
        Set(ByVal value As String)
            ViewState("passwordtext") = value
        End Set 

    End Property

    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Protected Overrides Sub LoadViewState(ByVal savedState As Object)

        Dim totalState As Object() = Nothing 
        If Not (savedState Is Nothing) Then
            totalState = CType(savedState, Object())
            If totalState.Length <> 3 Then 
                ' Throw an appropriate exception. 
            End If 
            ' Load base state. 
            MyBase.LoadViewState(totalState(0))
            ' Load extra information specific to this control. 
            If Not (totalState Is Nothing) AndAlso Not (totalState(1) Is Nothing) AndAlso Not (totalState(2) Is Nothing) Then
                UserText = CStr(totalState(1))
                PasswordText = CStr(totalState(2))
            End If 
        End If 

    End Sub

    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Protected Overrides Function SaveViewState() As Object 

        Dim baseState As Object = MyBase.SaveViewState()
        Dim totalState(2) As Object
        totalState(0) = baseState
        totalState(1) = user.Text
        totalState(2) = password.Text
        Return totalState

    End Function 
End Class

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

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.

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