WPF User Control Parent

donniefitz2 picture donniefitz2 · Nov 19, 2008 · Viewed 161.5k times · Source

I have a user control that I load into a MainWindow at runtime. I cannot get a handle on the containing window from the UserControl.

I have tried this.Parent, but it's always null. Does anyone know how to get a handle to the containing window from a user control in WPF?

Here is how the control is loaded:

private void XMLLogViewer_MenuItem_Click(object sender, RoutedEventArgs e)
{
    MenuItem application = sender as MenuItem;
    string parameter = application.CommandParameter as string;
    string controlName = parameter;
    if (uxPanel.Children.Count == 0)
    {
        System.Runtime.Remoting.ObjectHandle instance = Activator.CreateInstance(Assembly.GetExecutingAssembly().FullName, controlName);
        UserControl control = instance.Unwrap() as UserControl;
        this.LoadControl(control);
    }
}

private void LoadControl(UserControl control)
{
    if (uxPanel.Children.Count > 0)
    {
        foreach (UIElement ctrl in uxPanel.Children)
        {
            if (ctrl.GetType() != control.GetType())
            {
                this.SetControl(control);
            }
        }
    }
    else
    {
        this.SetControl(control);
    }
}

private void SetControl(UserControl control)
{
    control.Width = uxPanel.Width;
    control.Height = uxPanel.Height;
    uxPanel.Children.Add(control);
}

Answer

Ian Oakes picture Ian Oakes · Nov 20, 2008

Try using the following:

Window parentWindow = Window.GetWindow(userControlReference);

The GetWindow method will walk the VisualTree for you and locate the window that is hosting your control.

You should run this code after the control has loaded (and not in the Window constructor) to prevent the GetWindow method from returning null. E.g. wire up an event:

this.Loaded += new RoutedEventHandler(UserControl_Loaded);