AdvancedLauncher.Tools.Interop.RedirectedHwndHost.OnCurrentHwndSourceChanged C# (CSharp) Method

        protected virtual void OnCurrentHwndSourceChanged(DependencyPropertyChangedEventArgs e)
        {
            Initialize();

            // Unregister the old keyboard input site.
            IKeyboardInputSite keyboardInputSite = ((IKeyboardInputSink)this).KeyboardInputSite;
            if (keyboardInputSite != null) {
                ((IKeyboardInputSink)this).KeyboardInputSite = null;
                keyboardInputSite.Unregister();
            }

            // Register the new keyboard input site with the containing
            // HwndSource.
            IKeyboardInputSink sink = CurrentHwndSource;
            if (sink != null) {
                ((IKeyboardInputSink)this).KeyboardInputSite = sink.RegisterKeyboardInputSink(this);
            }

            // Set the owner of the RedirectedWindow to our CurrentHwndSource.
            // This keeps the RedirectedWindow on top of the HwndSource.
            if (CurrentHwndSource != null) {
                HWND hwndSource = new HWND(CurrentHwndSource.Handle);
                HWND hwndRoot = hwndSource; // User32NativeMethods.GetAncestor(hwndSource, GA.ROOT); // need to get the top-level window?
                NativeMethods.SetWindowLongPtr(
                    _redirectedWindow.Handle,
                    GWL.HWNDPARENT,
                    hwndRoot.DangerousGetHandle());
            }
        }