拦截另一个窗口的窗口消息

Posted 2023-02-22

【中文标题】拦截另一个窗口的窗口消息

【英文标题】：Intercepting Window Messages for another Window

【发布时间】：2013-12-19 19:27:07

【问题描述】：

我正在使用 CefGlue 制作一个带有嵌入式 webkit 浏览器的应用程序，我需要在浏览器窗口中监听鼠标移动。 winforms 控件不会将鼠标事件传递给控件，​​因此我无法监听它们。

但是，我发现了一个错误/功能请求，其中包含一个解决方案，但如何实现它超出了我的能力范围，我不熟悉直接在 WinAPI 中工作。开发人员说我需要：

2。特定于操作系统（windows） - 创建浏览器后（CefLifeSpanHandler.OnAfterCreated）获取窗口句柄和子类 它们（窗口子类化技术）。其实现在我们有本地人 具有类 CefBrowserWindow 的窗口（由 CefBrowser.GetHost().GetWindowHandle())，然后是子窗口 Chrome_WidgetWin_0，然后是 Chrome_RenderWidgetHostHWND。为了 拦截 WM_MOUSEMOVE 你对 Chrome_WidgetWin_0 感兴趣 窗口，可以通过 CefBrowserWindow 轻松获取。只是玩 用 Spy++ 精确查看。

https://bitbucket.org/xilium/xilium.cefglue/issue/4/mouse-events-unaccessible

我做了一些谷歌搜索，但我不知道如何挂钩。我的表单上有这个功能：

    [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
    protected override void WndProc(ref Message m) 
        base.WndProc(ref m);

        switch (m.Msg) 
            case WM_MOUSEMOVE:
                Console.WriteLine("Mouse move!");
                break;
            default:
                Console.WriteLine(m.ToString());
                break;
        
    

但是当我在控件上方时，我从来没有看到鼠标移动。我怀疑我需要监听CefBrowser.GetHost().GetWindowHandle() 的 WndProc，但我不知道该怎么做。

【问题讨论】：

见NativeWindow Class

【参考方案1】：

我找到了解决方案。我在 WebLifeSpanHandler 的 OnAfterCreated 事件中调用此函数。

        browser.Created += (sender, eventargs) => 
            Console.WriteLine("Created.");
            BrowserWindowPointer = browser.CefBrowser.GetHost().GetWindowHandle();
            Console.WriteLine("BrowserWindowPointer: " + BrowserWindowPointer);
            uint BrowserThreadId = GetWindowThreadProcessId(BrowserWindowPointer, IntPtr.Zero);
            Console.WriteLine("Browser PID: " + BrowserThreadId);

            MouseHookProcedure = new HookProc(this.MouseHookProc);

            hHookMouse = SetWindowsHookEx(WH_MOUSE,
                        MouseHookProcedure,
                        (IntPtr)0,
                        BrowserThreadId);

            if (hHookMouse == 0) 
                Console.WriteLine("MouseHook Failed. Making cursor always visible.");
                Cursor.Show();
            

            KeyboardHookProcedure = new HookProc(this.KeyboardHookProc);
            hHookKeyboard = SetWindowsHookEx(WH_KEYBOARD,
                        KeyboardHookProcedure,
                        (IntPtr)0,
                        BrowserThreadId);
        ;

我要找的函数是GetWindowThreadProcessId，我可以使用browser.CefBrowser.GetHost().GetWindowHandle()提供的窗口句柄

需要注意的一点是，Hook Procedure 需要具有某种更大的范围。 C# 看不到它与本机进程挂钩，如果你让它超出范围，它会被垃圾收集。为了解决这个问题，我将它们设为类属性。

支持文件：

http://support.microsoft.com/kb/318804

如何在 Visual C# .NET 中设置 Windows 挂钩

提供了挂钩鼠标事件的基础。修改为使用浏览器线程 id http://msdn.microsoft.com/en-us/library/ms644988(v=vs.85).aspx

MouseProc回调函数

如何处理鼠标windows钩子 http://msdn.microsoft.com/en-us/library/ms644984(VS.85).aspx

KeyboardProc 回调函数

如何处理键盘窗口挂钩。包括 lParam 的结构。重要提示：wParam 包含输入的键的虚拟键代码。 http://msdn.microsoft.com/en-us/library/dd375731(v=vs.85).aspx

Virtual-Key Codes

按键列表及其虚拟按键代码，这样我就可以知道用户按下了哪个按钮。

我的两个钩子（代码不好，我对封送数据不做任何事情）：

    private int MouseHookProc(int nCode, IntPtr wParam, IntPtr lParam) 
        //Marshall the data from the callback.
        MouseHookStruct MyMouseHookStruct = (MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseHookStruct));

        if (nCode < 0) 
            return CallNextHookEx(hHookMouse, nCode, wParam, lParam);
         else 
            if (wParam.ToInt32() == WM_MOUSEMOVE) 
                Screensaver_OnMouseMove(this, null);
            
            return CallNextHookEx(hHookMouse, nCode, wParam, lParam);
        
    

    private int KeyboardHookProc(int nCode, IntPtr wParam, IntPtr lParam) 
        //Marshall the data from the callback.
        KeyboardHookStruct keyInfo = (KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
        int VK_ESCAPE = 0x1B;

        if (nCode < 0) 
            return CallNextHookEx(hHookKeyboard, nCode, wParam, lParam);
         else 
            int keyCode = wParam.ToInt32();

            if (keyCode == VK_ESCAPE) 
                Application.Exit();
            

            return CallNextHookEx(hHookKeyboard, nCode, wParam, lParam);
        

    

这是暴露钩子所需的外部和代码，这是类级别的范围：

    public delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);

    //Declare the hook handle as an int.
    static int hHookMouse = 0;
    static int hHookKeyboard = 0;

    //Declare the mouse hook constant.
    //For other hook types, you can obtain these values from Winuser.h in the Microsoft SDK.
    private const int WH_KEYBOARD = 2;
    private const int WH_MOUSE = 7;
    private const int WM_MOUSEMOVE = 0x0200;

    //Declare the wrapper managed POINT class.
    [StructLayout(LayoutKind.Sequential)]
    public class POINT 
        public int x;
        public int y;
    

    //Declare the wrapper managed MouseHookStruct class.
    [StructLayout(LayoutKind.Sequential)]
    public class MouseHookStruct 
        public POINT pt;
        public int hwnd;
        public int wHitTestCode;
        public int dwExtraInfo;
    
    public struct KeyboardHookStruct 
        public int vkCode;
        public int scanCode;
        public int flags;
        public int time;
        public int dwExtraInfo;
    

    //This is the Import for the SetWindowsHookEx function.
    //Use this function to install a thread-specific hook.
    [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
    public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, uint threadId);

    //This is the Import for the UnhookWindowsHookEx function.
    //Call this function to uninstall the hook.
    [DllImport("user32.dll", CharSet = CharSet.Auto,
     CallingConvention = CallingConvention.StdCall)]
    public static extern bool UnhookWindowsHookEx(int idHook);

    //This is the Import for the CallNextHookEx function.
    //Use this function to pass the hook information to the next hook procedure in chain.
    [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
    public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll")]
    static extern uint GetWindowThreadProcessId(IntPtr hWnd, IntPtr ProcessId);

    public HookProc KeyboardHookProcedure  get; set; 

    public HookProc MouseHookProcedure  get; set; 

我不确定这是否完全需要，特别是因为被钩住的线程正在关闭，但为了更好地衡量，不要忘记在听完后清理你的钩子。我在表单的 dispose 方法上执行此操作：

    protected override void Dispose(bool disposing) 
        base.Dispose();

        if (disposing) 
            if (hHookKeyboard != 0) 
                UnhookWindowsHookEx(hHookKeyboard);
            
            if (hHookMouse != 0) 
                UnhookWindowsHookEx(hHookMouse);