AuthenticationService.Logout Method (Action<LogoutOperation>, Object)

Artigo
01/27/2012

[WCF RIA Services Version 1 Service Pack 2 is compatible with either .NET framework 4 or .NET Framework 4.5, and with either Silverlight 4 or Silverlight 5.]

Asynchronously logs out an authenticated user from the server with the specified callback method and user state.

Namespace: System.ServiceModel.DomainServices.Client.ApplicationServices
Assembly: System.ServiceModel.DomainServices.Client (in System.ServiceModel.DomainServices.Client.dll)

Syntax

'Declaration
Public Function Logout ( _
    completeAction As Action(Of LogoutOperation), _
    userState As Object _
) As LogoutOperation

'Usage
Dim instance As AuthenticationService
Dim completeAction As Action(Of LogoutOperation)
Dim userState As Object
Dim returnValue As LogoutOperation

returnValue = instance.Logout(completeAction, _
    userState)

public LogoutOperation Logout(
    Action<LogoutOperation> completeAction,
    Object userState
)

public:
LogoutOperation^ Logout(
    Action<LogoutOperation^>^ completeAction, 
    Object^ userState
)

member Logout : 
        completeAction:Action<LogoutOperation> * 
        userState:Object -> LogoutOperation

public function Logout(
    completeAction : Action<LogoutOperation>, 
    userState : Object
) : LogoutOperation

Parameters

completeAction
Type: System.Action<LogoutOperation>
An action that will be invoked immediately after the operation completes and is called in all cases, including success, cancellation, and error. This parameter is optional.

userState
Type: System.Object
The state that will be set into UserState. This parameter is optional.

Return Value

Type: System.ServiceModel.DomainServices.Client.ApplicationServices.LogoutOperation
The result of the operation.

Exceptions

Exception	Condition
InvalidOperationException	This method is called while another asynchronous operation is still being processed.

Remarks

If this method returns normally, a LoggedOut event may be raised. Also, successful completion of this operation will update the User. To handle an operation error, MarkErrorAsHandled can be called from the operation completion callback or from a Completed event handler.

Examples

The following example shows a call to the Logout method with a callback method.

Protected Overrides Sub OnNavigatedTo(ByVal e As System.Windows.Navigation.NavigationEventArgs)
    SetControlVisibility(WebContext.Current.User.IsAuthenticated)
End Sub

Private Sub LoginButton_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    Dim lp As LoginParameters = New LoginParameters(UserName.Text, Password.Password)
    WebContext.Current.Authentication.Login(lp, AddressOf Me.LoginOperation_Completed, Nothing)
    LoginButton.IsEnabled = False
    LoginResult.Text = ""
End Sub

Private Sub LoginOperation_Completed(ByVal lo As LoginOperation)
    If (lo.HasError) Then
        LoginResult.Text = lo.Error.Message
        LoginResult.Visibility = System.Windows.Visibility.Visible
        lo.MarkErrorAsHandled()
    ElseIf (lo.LoginSuccess = False) Then
        LoginResult.Text = "Login failed. Please check user name and password."
        LoginResult.Visibility = System.Windows.Visibility.Visible
    ElseIf (lo.LoginSuccess = True) Then
        SetControlVisibility(True)
    End If
    LoginButton.IsEnabled = True
End Sub

Private Sub SetControlVisibility(ByVal isAuthenticated As Boolean)
    If (isAuthenticated) Then
        LoginBorder.Visibility = System.Windows.Visibility.Collapsed
        WelcomeText.Text = "Welcome " + WebContext.Current.User.Name
        WelcomeText.Visibility = System.Windows.Visibility.Visible
        LogoutButton.Visibility = System.Windows.Visibility.Visible
    Else
        LoginBorder.Visibility = System.Windows.Visibility.Visible
        WelcomeText.Visibility = System.Windows.Visibility.Collapsed
        LogoutButton.Visibility = System.Windows.Visibility.Collapsed
    End If
End Sub

Private Sub LogoutButton_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    WebContext.Current.Authentication.Logout(AddressOf Me.LogoutOperation_Completed, Nothing)
End Sub

Private Sub LogoutOperation_Completed(ByVal lo As LogoutOperation)
    If (Not (lo.HasError)) Then
        SetControlVisibility(False)
    Else
        Dim ew As ErrorWindow = New ErrorWindow("Logout failed.", "Please try logging out again.")
        ew.Show()
        lo.MarkErrorAsHandled()
    End If
End Sub

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    SetControlVisibility(WebContext.Current.User.IsAuthenticated);
}

private void LoginButton_Click(object sender, RoutedEventArgs e)
{
    LoginParameters lp = new LoginParameters(UserName.Text, Password.Password);
    WebContext.Current.Authentication.Login(lp, this.LoginOperation_Completed, null);
    LoginButton.IsEnabled = false;
    LoginResult.Text = "";
}

private void LoginOperation_Completed(LoginOperation lo)
{
    if (lo.HasError)
    {
        LoginResult.Text = lo.Error.Message;
        LoginResult.Visibility = System.Windows.Visibility.Visible;
        lo.MarkErrorAsHandled();
    }
    else if (lo.LoginSuccess == false)
    {
        LoginResult.Text = "Login failed. Please check user name and password.";
        LoginResult.Visibility = System.Windows.Visibility.Visible;
    }
    else if (lo.LoginSuccess == true)
    {
        SetControlVisibility(true);
    }
    LoginButton.IsEnabled = true;
}

private void SetControlVisibility(bool isAuthenticated)
{
    if (isAuthenticated)
    {
        LoginBorder.Visibility = System.Windows.Visibility.Collapsed;
        WelcomeText.Text = "Welcome " + WebContext.Current.User.Name;
        WelcomeText.Visibility = System.Windows.Visibility.Visible;
        LogoutButton.Visibility = System.Windows.Visibility.Visible;
    }
    else
    {
        LoginBorder.Visibility = System.Windows.Visibility.Visible;
        WelcomeText.Visibility = System.Windows.Visibility.Collapsed;
        LogoutButton.Visibility = System.Windows.Visibility.Collapsed;
    }
}

private void LogoutButton_Click(object sender, RoutedEventArgs e)
{
    WebContext.Current.Authentication.Logout(this.LogoutOperation_Completed, null);
}

private void LogoutOperation_Completed(LogoutOperation lo)
{

    if (!lo.HasError)
    {
        SetControlVisibility(false);
    }
    else
    {
        ErrorWindow ew = new ErrorWindow("Logout failed.", "Please try logging out again.");
        ew.Show();
        lo.MarkErrorAsHandled();
    }
}

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