如何在WPF中处理WndProc消息？

xqnpmsa8 于 2023-02-25 发布在其他

关注(0)|答案(9)|浏览(322)

在Windows窗体中，我只需重写WndProc，并在消息传入时开始处理它们。
有人能给我一个例子，说明如何在WPF中实现同样的事情？

wpf

来源：https://stackoverflow.com/questions/624367/how-to-handle-wndproc-messages-in-wpf

9条答案

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bnlyeluc1#

您可以通过System.Windows.Interop命名空间来完成此操作，该命名空间包含一个名为HwndSource的类。
使用此选项的示例

using System;
using System.Windows;
using System.Windows.Interop;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        protected override void OnSourceInitialized(EventArgs e)
        {
            base.OnSourceInitialized(e);
            HwndSource source = PresentationSource.FromVisual(this) as HwndSource;
            source.AddHook(WndProc);
        }

        private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        {
            // Handle messages...

            return IntPtr.Zero;
        }
    }
}

完全取自优秀的博客文章：Using a custom WndProc in WPF apps by Steve Rands

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e4yzc0pl2#

实际上，据我所知，在WPF中使用HwndSource和HwndSourceHook确实可以做到这一点，以this thread on MSDN为例。（下面包含相关代码）

// 'this' is a Window
HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
source.AddHook(new HwndSourceHook(WndProc));

private static IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
    //  do stuff

    return IntPtr.Zero;
}

现在，我不太清楚为什么您希望在WPF应用程序中处理Windows Messaging消息（除非它是与另一个WinForms应用程序一起工作的最明显的互操作形式）。WPF中API的设计思想和性质与WinForms中非常不同，所以我建议您进一步熟悉WPF，以确切地了解 * 为什么 * 没有WndProc的等价物。

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f2uvfpb93#

HwndSource src = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
src.AddHook(new HwndSourceHook(WndProc));

.......

public IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{

  if(msg == THEMESSAGEIMLOOKINGFOR)
    {
      //Do something here
    }

  return IntPtr.Zero;
}

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evrscar24#

如果你不介意引用WinForms，你可以使用一个更面向MVVM的解决方案，它不将服务与视图耦合。你需要创建并初始化一个System.Windows.Forms.NativeWindow，它是一个可以接收消息的轻量级窗口。

public abstract class WinApiServiceBase : IDisposable
{
    /// <summary>
    /// Sponge window absorbs messages and lets other services use them
    /// </summary>
    private sealed class SpongeWindow : NativeWindow
    {
        public event EventHandler<Message> WndProced;
 
        public SpongeWindow()
        {
            CreateHandle(new CreateParams());
        }
 
        protected override void WndProc(ref Message m)
        {
            WndProced?.Invoke(this, m);
            base.WndProc(ref m);
        }
    }
 
    private static readonly SpongeWindow Sponge;
    protected static readonly IntPtr SpongeHandle;
 
    static WinApiServiceBase()
    {
        Sponge = new SpongeWindow();
        SpongeHandle = Sponge.Handle;
    }
 
    protected WinApiServiceBase()
    {
        Sponge.WndProced += LocalWndProced;
    }
 
    private void LocalWndProced(object sender, Message message)
    {
        WndProc(message);
    }
 
    /// <summary>
    /// Override to process windows messages
    /// </summary>
    protected virtual void WndProc(Message message)
    { }
 
    public virtual void Dispose()
    {
        Sponge.WndProced -= LocalWndProced;
    }
}

使用SpongeHandle注册您感兴趣的邮件，然后重写WndProc以处理它们：

public class WindowsMessageListenerService : WinApiServiceBase
{
    protected override void WndProc(Message message)
    {
        Debug.WriteLine(message.msg);
    }
}

唯一的缺点是必须包含System.Windows.Forms引用，但除此之外，这是一个非常封装的解决方案。

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92vpleto5#

以下是有关使用行为覆盖WindProc的链接：http://10rem.net/blog/2010/01/09/a-wpf-behavior-for-window-resize-events-in-net-35
[Edit：迟做总比不做好]下面是我基于上面链接的实现。虽然重新访问了这个，但我更喜欢AddHook实现。我可能会切换到那个。
在我的例子中，我想知道窗口什么时候被调整大小，以及其他一些事情。这个实现连接到Window xaml并发送事件。

using System;
using System.Windows.Interactivity;
using System.Windows; // For Window in behavior
using System.Windows.Interop; // For Hwnd

public class WindowResizeEvents : Behavior<Window>
    {
        public event EventHandler Resized;
        public event EventHandler Resizing;
        public event EventHandler Maximized;
        public event EventHandler Minimized;
        public event EventHandler Restored;

        public static DependencyProperty IsAppAskCloseProperty =  DependencyProperty.RegisterAttached("IsAppAskClose", typeof(bool), typeof(WindowResizeEvents));
        public Boolean IsAppAskClose
        {
            get { return (Boolean)this.GetValue(IsAppAskCloseProperty); }
            set { this.SetValue(IsAppAskCloseProperty, value); }
        }

        // called when the behavior is attached
        // hook the wndproc
        protected override void OnAttached()
        {
            base.OnAttached();

            AssociatedObject.Loaded += (s, e) =>
            {
                WireUpWndProc();
            };
        }

        // call when the behavior is detached
        // clean up our winproc hook
        protected override void OnDetaching()
        {
            RemoveWndProc();

            base.OnDetaching();
        }

        private HwndSourceHook _hook;

        private void WireUpWndProc()
        {
            HwndSource source = HwndSource.FromVisual(AssociatedObject) as HwndSource;

            if (source != null)
            {
                _hook = new HwndSourceHook(WndProc);
                source.AddHook(_hook);
            }
        }

        private void RemoveWndProc()
        {
            HwndSource source = HwndSource.FromVisual(AssociatedObject) as HwndSource;

            if (source != null)
            {
                source.RemoveHook(_hook);
            }
        }

        private const Int32 WM_EXITSIZEMOVE = 0x0232;
        private const Int32 WM_SIZING = 0x0214;
        private const Int32 WM_SIZE = 0x0005;

        private const Int32 SIZE_RESTORED = 0x0000;
        private const Int32 SIZE_MINIMIZED = 0x0001;
        private const Int32 SIZE_MAXIMIZED = 0x0002;
        private const Int32 SIZE_MAXSHOW = 0x0003;
        private const Int32 SIZE_MAXHIDE = 0x0004;

        private const Int32 WM_QUERYENDSESSION = 0x0011;
        private const Int32 ENDSESSION_CLOSEAPP = 0x1;
        private const Int32 WM_ENDSESSION = 0x0016;

        private IntPtr WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, ref Boolean handled)
        {
            IntPtr result = IntPtr.Zero;

            switch (msg)
            {
                case WM_SIZING:             // sizing gets interactive resize
                    OnResizing();
                    break;

                case WM_SIZE:               // size gets minimize/maximize as well as final size
                    {
                        int param = wParam.ToInt32();

                        switch (param)
                        {
                            case SIZE_RESTORED:
                                OnRestored();
                                break;
                            case SIZE_MINIMIZED:
                                OnMinimized();
                                break;
                            case SIZE_MAXIMIZED:
                                OnMaximized();
                                break;
                            case SIZE_MAXSHOW:
                                break;
                            case SIZE_MAXHIDE:
                                break;
                        }
                    }
                    break;

                case WM_EXITSIZEMOVE:
                    OnResized();
                    break;

                // Windows is requesting app to close.    
                // See http://msdn.microsoft.com/en-us/library/windows/desktop/aa376890%28v=vs.85%29.aspx.
                // Use the default response (yes).
                case WM_QUERYENDSESSION:
                    IsAppAskClose = true; 
                    break;
            }

            return result;
        }

        private void OnResizing()
        {
            if (Resizing != null)
                Resizing(AssociatedObject, EventArgs.Empty);
        }

        private void OnResized()
        {
            if (Resized != null)
                Resized(AssociatedObject, EventArgs.Empty);
        }

        private void OnRestored()
        {
            if (Restored != null)
                Restored(AssociatedObject, EventArgs.Empty);
        }

        private void OnMinimized()
        {
            if (Minimized != null)
                Minimized(AssociatedObject, EventArgs.Empty);
        }

        private void OnMaximized()
        {
            if (Maximized != null)
                Maximized(AssociatedObject, EventArgs.Empty);
        }
    }

<Window x:Class="MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml
        xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
        xmlns:behaviors="clr-namespace:RapidCoreConfigurator._Behaviors"
        Title="name" Height="500" Width="750" BorderBrush="Transparent">

    <i:Interaction.Behaviors>
        <behaviors:WindowResizeEvents IsAppAskClose="{Binding IsRequestClose, Mode=OneWayToSource}"
                                      Resized="Window_Resized"
                                      Resizing="Window_Resizing" />
    </i:Interaction.Behaviors>

    ... 

</Window>

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p8h8hvxi6#

您可以附加到内置Win32类的“SystemEvents”类：

using Microsoft.Win32;

在WPF窗口类中：

SystemEvents.PowerModeChanged += SystemEvents_PowerModeChanged;
SystemEvents.SessionSwitch += SystemEvents_SessionSwitch;
SystemEvents.SessionEnding += SystemEvents_SessionEnding;
SystemEvents.SessionEnded += SystemEvents_SessionEnded;

private async void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
    await vm.PowerModeChanged(e.Mode);
}

private async void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
    await vm.PowerModeChanged(e.Mode);
}

private async void SystemEvents_SessionSwitch(object sender, SessionSwitchEventArgs e)
{
    await vm.SessionSwitch(e.Reason);
}

private async void SystemEvents_SessionEnding(object sender, SessionEndingEventArgs e)
{
    if (e.Reason == SessionEndReasons.Logoff)
    {
        await vm.UserLogoff();
    }
}

private async void SystemEvents_SessionEnded(object sender, SessionEndedEventArgs e)
{
    if (e.Reason == SessionEndReasons.Logoff)
    {
        await vm.UserLogoff();
    }
}

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piok6c0g7#

在WPF中有一些方法可以使用WndProc处理消息（例如使用HwndSource等），但通常这些技术是为与不能直接通过WPF处理的消息进行互操作而保留的。大多数WPF控件甚至不是Win32（以及扩展为Windows.Forms）意义上的窗口，因此它们不会有WndProc。

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axr492tv8#

WPF不能在WinForms类型的wndprocs上运行
您可以在适当的WPF元素中托管HWndHost，然后重写Hwndhost的wndproc，但AFAIK是您最接近的方法。
http://msdn.microsoft.com/en-us/library/ms742522.aspx
http://blogs.msdn.com/nickkramer/archive/2006/03/18/554235.aspx

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hgtggwj09#

简单地说，你不能。WndProc通过将消息传递到Win32级别上的HWND来工作。WPF窗口没有HWND，因此不能参与WndProc消息。基本WPF消息循环确实位于WndProc之上，但它将它们从核心WPF逻辑中抽象出来。
您可以使用HWndHost并为其获取WndProc。但是，这几乎肯定不是您想要做的。对于大多数用途，WPF不在HWND和WndProc上操作。您的解决方案几乎肯定依赖于在WPF中而不是在WndProc中进行更改。

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