WPF User Control Parent

Question

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 hav

Answer 1

Gold plated edition of the above (I need a generic function which can infer a Window within the context of a MarkupExtension:-

public sealed class MyExtension : MarkupExtension
{
    public override object ProvideValue(IServiceProvider serviceProvider) =>
        new MyWrapper(ResolveRootObject(serviceProvider));
    object ResolveRootObject(IServiceProvider serviceProvider) => 
         GetService(serviceProvider).RootObject;
}

class MyWrapper
{
    object _rootObject;

    Window OwnerWindow() => WindowFromRootObject(_rootObject);

    static Window WindowFromRootObject(object root) =>
        (root as Window) ?? VisualParent((DependencyObject)root);
    static T VisualParent(DependencyObject node) where T : class
    {
        if (node == null)
            throw new InvalidOperationException("Could not locate a parent " + typeof(T).Name);
        var target = node as T;
        if (target != null)
            return target;
        return VisualParent(VisualTreeHelper.GetParent(node));
    }
}

MyWrapper.Owner() will correctly infer a Window on the following basis:

• the root Window by walking the visual tree (if used in the context of a UserControl)
• the window within which it is used (if it is used in the context of a Window's markup)