.net 我可以将WPF窗口覆盖在另一个窗口上吗？_.net_Wpf_Interop_Windowsformshost

.net 我可以将WPF窗口覆盖在另一个窗口上吗？

.net wpf

.net 我可以将WPF窗口覆盖在另一个窗口上吗？,.net,wpf,interop,windowsformshost,.net,Wpf,Interop,Windowsformshost,我有一个WPF窗口，其中包含一个WindowsFormsHost元素。我需要在这个元素的顶部绘制东西，但是WindowsFormsHost的性质意味着它总是在绘图堆的顶部。由于我无法在WindowsFormsHost组件顶部绘制相同的WPF窗口，我可以在其顶部覆盖另一个窗口吗我已经初步尝试过了，但我有几个问题： 1）我无法阻止其他应用程序在主窗口和覆盖窗口之间运行windows 2）当我选择Alt Tab时，叠加窗口出现在窗口列表中，这非常难看基本上，我需要一个“子窗口”的概念，这个窗口

我有一个WPF窗口，其中包含一个

WindowsFormsHost

元素。我需要在这个元素的顶部绘制东西，但是

WindowsFormsHost

的性质意味着它总是在绘图堆的顶部。由于我无法在

WindowsFormsHost

组件顶部绘制相同的WPF窗口，我可以在其顶部覆盖另一个窗口吗

我已经初步尝试过了，但我有几个问题：

1）我无法阻止其他应用程序在主窗口和覆盖窗口之间运行windows

2）当我选择Alt Tab时，叠加窗口出现在窗口列表中，这非常难看

基本上，我需要一个“子窗口”的概念，这个窗口在所有意图和目的上都是另一个窗口的一部分。用户控件对我不起作用，因为

WindowsFormsHost

总是在它上面绘制

有什么想法吗

更新[2011年5月23日10:13]

谢谢你们两位的回答

我尝试了

ChildWindow

方法，而

WindowsFormsHost

元素仍然在顶部绘制。据我所知，只有真正的窗口才能在

WindowsFormsHost

上绘制，同一窗口中的任何内容都将位于

WindowsFormsHost

下

<Grid>
    <local:AirspacePopup PlacementTarget="{Binding ElementName=webBrowser}"
                         FollowPlacementTarget="True"
                         AllowOutsideScreenPlacement="True"
                         ParentWindow="{Binding RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
                         IsOpen="True"
                         AllowsTransparency="True"
                         Placement="Center"
                         Width="{Binding ElementName=googleBrowser, Path=ActualWidth}"
                         Height="{Binding ElementName=googleBrowser, Path=ActualHeight}">
        <Grid>
            <Ellipse Width="100" Height="100" Fill="Green" Margin="100"/>
        </Grid>
    </local:AirspacePopup>
    <WebBrowser Name="webBrowser" Loaded="WebBrowser_Loaded"/>
</Grid>

带有

WindowsFormsHost

的元素仍将在WinForms组件下绘制，它们始终绘制在顶部，这似乎是不可协商的

我想我要找的是一种方法，可以停靠一个外部窗口，作为主窗口的一部分。在Mac电脑上，有一个真正的“子窗口”的概念，我正在寻找类似的东西。

你可以在

WindowsFormsHost

中做“覆盖”部分。因此，您可以在托管元素中的其他内容之上有一个子元素。

在使用CAL或事件聚合器的典型MVP应用程序中，您可能需要创建另一个窗口并将其命名为popup或child（

ChildWindow.XAML

），并在（

ChildWindow.XAML.CS

）中有一个get方法，如

在maniwindow中有一个属性，可以在需要时返回Childwindow类型。像

希望这能有所帮助，

我已经通过使用

弹出窗口而不是透明的窗口解决了这个问题
更新
我最终得到了一个子类Popup
，我称之为airspaceppopup

AirspacePopup
的作用是什么

遵循其位置目标
不总是在顶部，而是相对于要放置它的窗口
放置。这个解决方案来自于
允许移动到“屏幕外”。这是通过剪切弹出窗口
并在其子项移出屏幕后设置负的边距来实现的。这个解决方案来自Rick Sladkey

下面是一个示例，其中使用AirspacePopup
在WebBrowser
控件（实际上是一个WinForms控件）上绘制一个Ellipse
，但它同样适用于任何WindowsFormsHost

<Grid>
    <local:AirspacePopup PlacementTarget="{Binding ElementName=webBrowser}"
                         FollowPlacementTarget="True"
                         AllowOutsideScreenPlacement="True"
                         ParentWindow="{Binding RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
                         IsOpen="True"
                         AllowsTransparency="True"
                         Placement="Center"
                         Width="{Binding ElementName=googleBrowser, Path=ActualWidth}"
                         Height="{Binding ElementName=googleBrowser, Path=ActualHeight}">
        <Grid>
            <Ellipse Width="100" Height="100" Fill="Green" Margin="100"/>
        </Grid>
    </local:AirspacePopup>
    <WebBrowser Name="webBrowser" Loaded="WebBrowser_Loaded"/>
</Grid>

空中空间弹出窗口
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Input;
using System.Windows.Interop;

public class AirspacePopup : Popup
{
    public static readonly DependencyProperty IsTopmostProperty =
        DependencyProperty.Register("IsTopmost",
                                    typeof(bool),
                                    typeof(AirspacePopup),
                                    new FrameworkPropertyMetadata(false, OnIsTopmostChanged));

    public static readonly DependencyProperty FollowPlacementTargetProperty =
        DependencyProperty.RegisterAttached("FollowPlacementTarget",
                                            typeof(bool),
                                            typeof(AirspacePopup),
                                            new UIPropertyMetadata(false));

    public static readonly DependencyProperty AllowOutsideScreenPlacementProperty =
        DependencyProperty.RegisterAttached("AllowOutsideScreenPlacement",
                                            typeof(bool),
                                            typeof(AirspacePopup),
                                            new UIPropertyMetadata(false));

    public static readonly DependencyProperty ParentWindowProperty =
        DependencyProperty.RegisterAttached("ParentWindow",
                                            typeof(Window),
                                            typeof(AirspacePopup),
                                            new UIPropertyMetadata(null, ParentWindowPropertyChanged));

    private static void OnIsTopmostChanged(DependencyObject source, DependencyPropertyChangedEventArgs e)
    {
        AirspacePopup airspacePopup = source as AirspacePopup;
        airspacePopup.SetTopmostState(airspacePopup.IsTopmost);
    }

    private static void ParentWindowPropertyChanged(DependencyObject source, DependencyPropertyChangedEventArgs e)
    {
        AirspacePopup airspacePopup = source as AirspacePopup;
        airspacePopup.ParentWindowChanged();
    }

    private bool? m_appliedTopMost;
    private bool m_alreadyLoaded;
    private Window m_parentWindow;

    public AirspacePopup()
    {
        Loaded += OnPopupLoaded;
        Unloaded += OnPopupUnloaded;

        DependencyPropertyDescriptor descriptor = DependencyPropertyDescriptor.FromProperty(PlacementTargetProperty, typeof(AirspacePopup));
        descriptor.AddValueChanged(this, PlacementTargetChanged);
    }

    public bool IsTopmost
    {
        get { return (bool)GetValue(IsTopmostProperty); }
        set { SetValue(IsTopmostProperty, value); }
    }
    public bool FollowPlacementTarget
    {
        get { return (bool)GetValue(FollowPlacementTargetProperty); }
        set { SetValue(FollowPlacementTargetProperty, value); }
    }
    public bool AllowOutsideScreenPlacement
    {
        get { return (bool)GetValue(AllowOutsideScreenPlacementProperty); }
        set { SetValue(AllowOutsideScreenPlacementProperty, value); }
    }
    public Window ParentWindow
    {
        get { return (Window)GetValue(ParentWindowProperty); }
        set { SetValue(ParentWindowProperty, value); }
    }

    private void ParentWindowChanged()
    {
        if (ParentWindow != null)
        {
            ParentWindow.LocationChanged += (sender, e2) =>
            {
                UpdatePopupPosition();
            };
            ParentWindow.SizeChanged += (sender, e2) =>
            {
                UpdatePopupPosition();
            };
        }
    }
    private void PlacementTargetChanged(object sender, EventArgs e)
    {
        FrameworkElement placementTarget = this.PlacementTarget as FrameworkElement;
        if (placementTarget != null)
        {
            placementTarget.SizeChanged += (sender2, e2) =>
            {
                UpdatePopupPosition();
            };
        }
    }

    private void UpdatePopupPosition()
    {
        FrameworkElement placementTarget = this.PlacementTarget as FrameworkElement;
        FrameworkElement child = this.Child as FrameworkElement;

        if (PresentationSource.FromVisual(placementTarget) != null &&
            AllowOutsideScreenPlacement == true)
        {
            double leftOffset = CutLeft(placementTarget);
            double topOffset = CutTop(placementTarget);
            double rightOffset = CutRight(placementTarget);
            double bottomOffset = CutBottom(placementTarget);
            Debug.WriteLine(bottomOffset);
            this.Width = Math.Max(0, Math.Min(leftOffset, rightOffset) + placementTarget.ActualWidth);
            this.Height = Math.Max(0, Math.Min(topOffset, bottomOffset) + placementTarget.ActualHeight);

            if (child != null)
            {
                child.Margin = new Thickness(leftOffset, topOffset, rightOffset, bottomOffset);
            }
        }
        if (FollowPlacementTarget == true)
        {
            this.HorizontalOffset += 0.01;
            this.HorizontalOffset -= 0.01;
        }
    }
    private double CutLeft(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(0, placementTarget.ActualWidth));
        return Math.Min(0, point.X);
    }
    private double CutTop(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(placementTarget.ActualHeight, 0));
        return Math.Min(0, point.Y);
    }
    private double CutRight(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(0, placementTarget.ActualWidth));
        point.X += placementTarget.ActualWidth;
        return Math.Min(0, SystemParameters.VirtualScreenWidth - (Math.Max(SystemParameters.VirtualScreenWidth, point.X)));
    }
    private double CutBottom(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(placementTarget.ActualHeight, 0));
        point.Y += placementTarget.ActualHeight;
        return Math.Min(0, SystemParameters.VirtualScreenHeight - (Math.Max(SystemParameters.VirtualScreenHeight, point.Y)));
    }

    private void OnPopupLoaded(object sender, RoutedEventArgs e)
    {
        if (m_alreadyLoaded) 
            return;

        m_alreadyLoaded = true;

        if (Child != null)
        {
            Child.AddHandler(PreviewMouseLeftButtonDownEvent, new MouseButtonEventHandler(OnChildPreviewMouseLeftButtonDown), true);
        }

        m_parentWindow = Window.GetWindow(this);

        if (m_parentWindow == null) 
            return;

        m_parentWindow.Activated += OnParentWindowActivated;
        m_parentWindow.Deactivated += OnParentWindowDeactivated;
    }

    private void OnPopupUnloaded(object sender, RoutedEventArgs e)
    {
        if (m_parentWindow == null)
            return;
        m_parentWindow.Activated -= OnParentWindowActivated;
        m_parentWindow.Deactivated -= OnParentWindowDeactivated;
    }

    private void OnParentWindowActivated(object sender, EventArgs e)
    {
        SetTopmostState(true);
    }

    private void OnParentWindowDeactivated(object sender, EventArgs e)
    {
        if (IsTopmost == false)
        {
            SetTopmostState(IsTopmost);
        }
    }

    private void OnChildPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        SetTopmostState(true);
        if (!m_parentWindow.IsActive && IsTopmost == false)
        {
            m_parentWindow.Activate();
        }
    }

    protected override void OnOpened(EventArgs e)
    {
        SetTopmostState(IsTopmost);
        base.OnOpened(e);
    }

    private void SetTopmostState(bool isTop)
    {
        // Don’t apply state if it’s the same as incoming state
        if (m_appliedTopMost.HasValue && m_appliedTopMost == isTop)
        {
            return;
        }

        if (Child == null) 
            return;

        var hwndSource = (PresentationSource.FromVisual(Child)) as HwndSource;

        if (hwndSource == null) 
            return;
        var hwnd = hwndSource.Handle;

        RECT rect;

        if (!GetWindowRect(hwnd, out rect)) 
            return;

        Debug.WriteLine("setting z-order " + isTop);

        if (isTop)
        {
            SetWindowPos(hwnd, HWND_TOPMOST, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
        }
        else
        {
            // Z-Order would only get refreshed/reflected if clicking the
            // the titlebar (as opposed to other parts of the external
            // window) unless I first set the popup to HWND_BOTTOM
            // then HWND_TOP before HWND_NOTOPMOST
            SetWindowPos(hwnd, HWND_BOTTOM, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
            SetWindowPos(hwnd, HWND_TOP, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
            SetWindowPos(hwnd, HWND_NOTOPMOST, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
        }

        m_appliedTopMost = isTop;
    }

    #region P/Invoke imports & definitions
    #pragma warning disable 1591 //Xml-doc
    #pragma warning disable 169 //Never used-warning
    // ReSharper disable InconsistentNaming
    // Imports etc. with their naming rules

    [StructLayout(LayoutKind.Sequential)]
    public struct RECT

    {
        public int Left;
        public int Top;
        public int Right;
        public int Bottom;
    }

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);

    [DllImport("user32.dll")]
    private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X,
    int Y, int cx, int cy, uint uFlags);

    static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
    static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);
    static readonly IntPtr HWND_TOP = new IntPtr(0);
    static readonly IntPtr HWND_BOTTOM = new IntPtr(1);

    private const UInt32 SWP_NOSIZE = 0x0001;
    const UInt32 SWP_NOMOVE = 0x0002;
    const UInt32 SWP_NOZORDER = 0x0004;
    const UInt32 SWP_NOREDRAW = 0x0008;
    const UInt32 SWP_NOACTIVATE = 0x0010;

    const UInt32 SWP_FRAMECHANGED = 0x0020; /* The frame changed: send WM_NCCALCSIZE */
    const UInt32 SWP_SHOWWINDOW = 0x0040;
    const UInt32 SWP_HIDEWINDOW = 0x0080;
    const UInt32 SWP_NOCOPYBITS = 0x0100;
    const UInt32 SWP_NOOWNERZORDER = 0x0200; /* Don’t do owner Z ordering */
    const UInt32 SWP_NOSENDCHANGING = 0x0400; /* Don’t send WM_WINDOWPOSCHANGING */

    const UInt32 TOPMOST_FLAGS = 
        SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOSIZE | SWP_NOMOVE | SWP_NOREDRAW | SWP_NOSENDCHANGING;

    // ReSharper restore InconsistentNaming
    #pragma warning restore 1591
    #pragma warning restore 169
    #endregion
}

我建议用这个
我一直在努力解决这个问题有一段时间了，发现MahApps库在没有任何配置的情况下修复了空域问题。有关更多信息，请参阅他们的常见问题解答：
对不同的溶液进行大量测试后：
Microsoft.dwayneeed（）




赞成的意见：
就我所知，工作得很好（我没有对它进行过太多测试，但它看起来很像）
这场演出似乎太低了



欺骗：
相对较大的图书馆。



空中定位器（）




赞成的意见：
效果很好（没有测试过那么多，但看起来很像）


欺骗：
有一个小的性能冲击。（据我所知，比Microsoft.dwayneed更大）



Fredrik Hedblad（）




赞成的意见：
简单的代码。主要是：D


欺骗：

在全屏上，底部的一部分缺失
多监视器问题：当从一个窗口移动到另一个窗口时，覆盖并不完全覆盖winformshostwindow。

对我来说，最好的解决方案是使用Microsoft.dwayneed。（我用它将Winforms导入WPF应用程序）
因为让它工作并不是简单的，她只是一个小教程：
去
单击下载
打开Microsoft.dwayneeed.sln
编译它
在创建的调试或Releas文件夹中引用Microsoft.dwayneeed.dll
加
xmlns:interop=“clr命名空间：Microsoft.dwayneeed.interop；assembly=Microsoft.dwayneeed
到你的窗口
加
到你的网格
例如：


如何使此HitTestVisible可见？我尝试将网格背景设置为“透明”，但无效。当我将背景设置为“白色”时“并将“不透明度”设置为0.01它是可见的！也许有人有想法？当窗口最大化时，底部有一个小间隙，弹出窗口不能正确跟随。如何解决此问题？从最小化状态恢复窗口时，dwm动画无法很好地解决此问题。当主窗口仍在设置动画时，椭圆立即出现。有解决方案吗？截至2021年，似乎仍然是没有WinAPI的最可靠的解决方案，第三方库对我不起作用：System.NullReferenceException对象引用未设置为对象的实例。位于Microsoft.dwayneed.Interop.RedirectedHwndHost.UpdateOutputRedirection（）的Microsoft.dwayneed.Interop.RedirectedHwndHost.b_u_31_2（对象e，事件参数a）的System.Windows.Threading.Dispatchermer.FireTick（未使用的对象）的System.Windows.Threading.ExceptionWra
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void WebBrowser_Loaded(object sender, RoutedEventArgs e)
    {
        WebBrowser webbrowser = sender as WebBrowser;
        webbrowser.Navigate("http://www.stackoverflow.com");
    }
}

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Input;
using System.Windows.Interop;

public class AirspacePopup : Popup
{
    public static readonly DependencyProperty IsTopmostProperty =
        DependencyProperty.Register("IsTopmost",
                                    typeof(bool),
                                    typeof(AirspacePopup),
                                    new FrameworkPropertyMetadata(false, OnIsTopmostChanged));

    public static readonly DependencyProperty FollowPlacementTargetProperty =
        DependencyProperty.RegisterAttached("FollowPlacementTarget",
                                            typeof(bool),
                                            typeof(AirspacePopup),
                                            new UIPropertyMetadata(false));

    public static readonly DependencyProperty AllowOutsideScreenPlacementProperty =
        DependencyProperty.RegisterAttached("AllowOutsideScreenPlacement",
                                            typeof(bool),
                                            typeof(AirspacePopup),
                                            new UIPropertyMetadata(false));

    public static readonly DependencyProperty ParentWindowProperty =
        DependencyProperty.RegisterAttached("ParentWindow",
                                            typeof(Window),
                                            typeof(AirspacePopup),
                                            new UIPropertyMetadata(null, ParentWindowPropertyChanged));

    private static void OnIsTopmostChanged(DependencyObject source, DependencyPropertyChangedEventArgs e)
    {
        AirspacePopup airspacePopup = source as AirspacePopup;
        airspacePopup.SetTopmostState(airspacePopup.IsTopmost);
    }

    private static void ParentWindowPropertyChanged(DependencyObject source, DependencyPropertyChangedEventArgs e)
    {
        AirspacePopup airspacePopup = source as AirspacePopup;
        airspacePopup.ParentWindowChanged();
    }

    private bool? m_appliedTopMost;
    private bool m_alreadyLoaded;
    private Window m_parentWindow;

    public AirspacePopup()
    {
        Loaded += OnPopupLoaded;
        Unloaded += OnPopupUnloaded;

        DependencyPropertyDescriptor descriptor = DependencyPropertyDescriptor.FromProperty(PlacementTargetProperty, typeof(AirspacePopup));
        descriptor.AddValueChanged(this, PlacementTargetChanged);
    }

    public bool IsTopmost
    {
        get { return (bool)GetValue(IsTopmostProperty); }
        set { SetValue(IsTopmostProperty, value); }
    }
    public bool FollowPlacementTarget
    {
        get { return (bool)GetValue(FollowPlacementTargetProperty); }
        set { SetValue(FollowPlacementTargetProperty, value); }
    }
    public bool AllowOutsideScreenPlacement
    {
        get { return (bool)GetValue(AllowOutsideScreenPlacementProperty); }
        set { SetValue(AllowOutsideScreenPlacementProperty, value); }
    }
    public Window ParentWindow
    {
        get { return (Window)GetValue(ParentWindowProperty); }
        set { SetValue(ParentWindowProperty, value); }
    }

    private void ParentWindowChanged()
    {
        if (ParentWindow != null)
        {
            ParentWindow.LocationChanged += (sender, e2) =>
            {
                UpdatePopupPosition();
            };
            ParentWindow.SizeChanged += (sender, e2) =>
            {
                UpdatePopupPosition();
            };
        }
    }
    private void PlacementTargetChanged(object sender, EventArgs e)
    {
        FrameworkElement placementTarget = this.PlacementTarget as FrameworkElement;
        if (placementTarget != null)
        {
            placementTarget.SizeChanged += (sender2, e2) =>
            {
                UpdatePopupPosition();
            };
        }
    }

    private void UpdatePopupPosition()
    {
        FrameworkElement placementTarget = this.PlacementTarget as FrameworkElement;
        FrameworkElement child = this.Child as FrameworkElement;

        if (PresentationSource.FromVisual(placementTarget) != null &&
            AllowOutsideScreenPlacement == true)
        {
            double leftOffset = CutLeft(placementTarget);
            double topOffset = CutTop(placementTarget);
            double rightOffset = CutRight(placementTarget);
            double bottomOffset = CutBottom(placementTarget);
            Debug.WriteLine(bottomOffset);
            this.Width = Math.Max(0, Math.Min(leftOffset, rightOffset) + placementTarget.ActualWidth);
            this.Height = Math.Max(0, Math.Min(topOffset, bottomOffset) + placementTarget.ActualHeight);

            if (child != null)
            {
                child.Margin = new Thickness(leftOffset, topOffset, rightOffset, bottomOffset);
            }
        }
        if (FollowPlacementTarget == true)
        {
            this.HorizontalOffset += 0.01;
            this.HorizontalOffset -= 0.01;
        }
    }
    private double CutLeft(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(0, placementTarget.ActualWidth));
        return Math.Min(0, point.X);
    }
    private double CutTop(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(placementTarget.ActualHeight, 0));
        return Math.Min(0, point.Y);
    }
    private double CutRight(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(0, placementTarget.ActualWidth));
        point.X += placementTarget.ActualWidth;
        return Math.Min(0, SystemParameters.VirtualScreenWidth - (Math.Max(SystemParameters.VirtualScreenWidth, point.X)));
    }
    private double CutBottom(FrameworkElement placementTarget)
    {
        Point point = placementTarget.PointToScreen(new Point(placementTarget.ActualHeight, 0));
        point.Y += placementTarget.ActualHeight;
        return Math.Min(0, SystemParameters.VirtualScreenHeight - (Math.Max(SystemParameters.VirtualScreenHeight, point.Y)));
    }

    private void OnPopupLoaded(object sender, RoutedEventArgs e)
    {
        if (m_alreadyLoaded) 
            return;

        m_alreadyLoaded = true;

        if (Child != null)
        {
            Child.AddHandler(PreviewMouseLeftButtonDownEvent, new MouseButtonEventHandler(OnChildPreviewMouseLeftButtonDown), true);
        }

        m_parentWindow = Window.GetWindow(this);

        if (m_parentWindow == null) 
            return;

        m_parentWindow.Activated += OnParentWindowActivated;
        m_parentWindow.Deactivated += OnParentWindowDeactivated;
    }

    private void OnPopupUnloaded(object sender, RoutedEventArgs e)
    {
        if (m_parentWindow == null)
            return;
        m_parentWindow.Activated -= OnParentWindowActivated;
        m_parentWindow.Deactivated -= OnParentWindowDeactivated;
    }

    private void OnParentWindowActivated(object sender, EventArgs e)
    {
        SetTopmostState(true);
    }

    private void OnParentWindowDeactivated(object sender, EventArgs e)
    {
        if (IsTopmost == false)
        {
            SetTopmostState(IsTopmost);
        }
    }

    private void OnChildPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        SetTopmostState(true);
        if (!m_parentWindow.IsActive && IsTopmost == false)
        {
            m_parentWindow.Activate();
        }
    }

    protected override void OnOpened(EventArgs e)
    {
        SetTopmostState(IsTopmost);
        base.OnOpened(e);
    }

    private void SetTopmostState(bool isTop)
    {
        // Don’t apply state if it’s the same as incoming state
        if (m_appliedTopMost.HasValue && m_appliedTopMost == isTop)
        {
            return;
        }

        if (Child == null) 
            return;

        var hwndSource = (PresentationSource.FromVisual(Child)) as HwndSource;

        if (hwndSource == null) 
            return;
        var hwnd = hwndSource.Handle;

        RECT rect;

        if (!GetWindowRect(hwnd, out rect)) 
            return;

        Debug.WriteLine("setting z-order " + isTop);

        if (isTop)
        {
            SetWindowPos(hwnd, HWND_TOPMOST, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
        }
        else
        {
            // Z-Order would only get refreshed/reflected if clicking the
            // the titlebar (as opposed to other parts of the external
            // window) unless I first set the popup to HWND_BOTTOM
            // then HWND_TOP before HWND_NOTOPMOST
            SetWindowPos(hwnd, HWND_BOTTOM, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
            SetWindowPos(hwnd, HWND_TOP, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
            SetWindowPos(hwnd, HWND_NOTOPMOST, rect.Left, rect.Top, (int)Width, (int)Height, TOPMOST_FLAGS);
        }

        m_appliedTopMost = isTop;
    }

    #region P/Invoke imports & definitions
    #pragma warning disable 1591 //Xml-doc
    #pragma warning disable 169 //Never used-warning
    // ReSharper disable InconsistentNaming
    // Imports etc. with their naming rules

    [StructLayout(LayoutKind.Sequential)]
    public struct RECT

    {
        public int Left;
        public int Top;
        public int Right;
        public int Bottom;
    }

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);

    [DllImport("user32.dll")]
    private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X,
    int Y, int cx, int cy, uint uFlags);

    static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
    static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);
    static readonly IntPtr HWND_TOP = new IntPtr(0);
    static readonly IntPtr HWND_BOTTOM = new IntPtr(1);

    private const UInt32 SWP_NOSIZE = 0x0001;
    const UInt32 SWP_NOMOVE = 0x0002;
    const UInt32 SWP_NOZORDER = 0x0004;
    const UInt32 SWP_NOREDRAW = 0x0008;
    const UInt32 SWP_NOACTIVATE = 0x0010;

    const UInt32 SWP_FRAMECHANGED = 0x0020; /* The frame changed: send WM_NCCALCSIZE */
    const UInt32 SWP_SHOWWINDOW = 0x0040;
    const UInt32 SWP_HIDEWINDOW = 0x0080;
    const UInt32 SWP_NOCOPYBITS = 0x0100;
    const UInt32 SWP_NOOWNERZORDER = 0x0200; /* Don’t do owner Z ordering */
    const UInt32 SWP_NOSENDCHANGING = 0x0400; /* Don’t send WM_WINDOWPOSCHANGING */

    const UInt32 TOPMOST_FLAGS = 
        SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOSIZE | SWP_NOMOVE | SWP_NOREDRAW | SWP_NOSENDCHANGING;

    // ReSharper restore InconsistentNaming
    #pragma warning restore 1591
    #pragma warning restore 169
    #endregion
}

xmlns:interop="clr-namespace:Microsoft.DwayneNeed.Interop;assembly=Microsoft.DwayneNeed
<interop:AirspaceDecorator AirspaceMode="Redirect" Background="White" IsInputRedirectionEnabled="True" IsOutputRedirectionEnabled="True">
<WindowsFormsHost x:Name="windowsFormsHost1" Visibility="Visible" />
</interop:AirspaceDecorator>