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UserControl.SaveViewState Método

  • Referencia

Definición

Espacio de nombres:
System.Web.UI
Ensamblado:
System.Web.dll

Guarda todos los cambios del estado de vista del control de usuario que se han producido desde el último postback de la página.

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

Devoluciones

Object

Devuelve el estado de vista actual del control de usuario. Si no hay un estado de vista asociado al control, devuelve null.

Ejemplos

En el ejemplo siguiente se muestra un control de usuario que administra su estado de vista mediante los LoadViewState métodos y SaveViewState .

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

Comentarios

En general, no es necesario llamar a este método. Sin embargo, si almacena información personalizada en estado de vista, puede invalidar este método para hacerlo.

Se aplica a

Consulte también