UserControl.SaveViewState Methode

Definitie

Naamruimte:
System.Web.UI
Assembly:
System.Web.dll

Hiermee worden wijzigingen in de weergavestatus van gebruikersbeheer opgeslagen die zijn opgetreden sinds de laatste postback van de pagina.

protected:
 override System::Object ^ SaveViewState();
protected override object SaveViewState();
override this.SaveViewState : unit -> obj
Protected Overrides Function SaveViewState () As Object

Retouren

Object

Retourneert de huidige weergavestatus van het gebruikersbeheer. Als er geen weergavestatus is gekoppeld aan het besturingselement, wordt deze geretourneerd null.

Voorbeelden

In het volgende voorbeeld ziet u een gebruikersbeheer waarmee de weergavestatus wordt beheerd met behulp van de LoadViewState en SaveViewState methoden.

public string UserText
{
    get
    {
        return (string)ViewState["usertext"];
    }
    set
    {
        ViewState["usertext"] = value;
    }
}
public string PasswordText
{
    get
    {
        return (string)ViewState["passwordtext"];
    }
    set
    {
        ViewState["passwordtext"] = value;
    }
}

[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
protected override void LoadViewState(object savedState) 
{
    object[] totalState = null;	   
    if (savedState != null)
    {
        totalState = (object[])savedState;
        if (totalState.Length != 3)
        {
            // Throw an appropriate exception.
        }
        // Load base state.
        base.LoadViewState(totalState[0]);
        // Load extra information specific to this control.
        if (totalState != null && totalState[1] != null && totalState[2] != null)
        {
            UserText = (string)totalState[1];
            PasswordText = (string)totalState[2];
        }
    }
}

[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
protected override object SaveViewState()
{
    object baseState = base.SaveViewState();
    object[] totalState = new object[3];
    totalState[0] = baseState;
    totalState[1] = user.Text;
    totalState[2] = password.Text;
    return totalState;
}

   
    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

Opmerkingen

Over het algemeen hoeft u deze methode niet aan te roepen. Als u echter aangepaste gegevens opslaat in de weergavestatus, kunt u deze methode overschrijven om dit te doen.

Van toepassing op

Zie ook