全局鼠标事件处理程序

  • Z时代
  • 2024-01-10
  • 分类：问答

我有以下代码是从某处获取的以捕获鼠标事件。我修改了它，并制作了一个事件处理程序，以便可以订阅它。鼠标事件被正确捕获。但是它永远不会触发事件处理程序。有人能找出代码有什么问题吗？

public static class MouseHook
{
    public static event EventHandler MouseAction = delegate { };
    public static void Start()
    {
        _hookID = SetHook(_proc);
    }
    public static void stop()
    {
        UnhookWindowsHookEx(_hookID);
    }
    private static LowLevelMouseProc _proc = HookCallback;
    private static IntPtr _hookID = IntPtr.Zero;
    private static IntPtr SetHook(LowLevelMouseProc proc)
    {
        using (Process curProcess = Process.GetCurrentProcess())
        using (ProcessModule curModule = curProcess.MainModule)
        {
            return SetWindowsHookEx(WH_MOUSE_LL, proc,
              GetModuleHandle(curModule.ModuleName), 0);
        }
    }
    private delegate IntPtr LowLevelMouseProc(int nCode, IntPtr wParam, IntPtr lParam);
    private static IntPtr HookCallback(
      int nCode, IntPtr wParam, IntPtr lParam)
    {
        if (nCode >= 0 && MouseMessages.WM_LBUTTONDOWN == (MouseMessages)wParam)
        {
           MSLLHOOKSTRUCT hookStruct = (MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));  
           MouseAction(null,new EventArgs());
        }
        return CallNextHookEx(_hookID, nCode, wParam, lParam);
    }
    private const int WH_MOUSE_LL = 14;
    private enum MouseMessages
    {
        WM_LBUTTONDOWN = 0x0201,
        WM_LBUTTONUP = 0x0202,
        WM_MOUSEMOVE = 0x0200,
        WM_MOUSEWHEEL = 0x020A,
        WM_RBUTTONDOWN = 0x0204,
        WM_RBUTTONUP = 0x0205
    }
    [StructLayout(LayoutKind.Sequential)]
    private struct POINT
    {
        public int x;
        public int y;
    }
    [StructLayout(LayoutKind.Sequential)]
    private struct MSLLHOOKSTRUCT
    {
        public POINT pt;
        public uint mouseData;
        public uint flags;
        public uint time;
        public IntPtr dwExtraInfo;
    }
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook,
      LowLevelMouseProc lpfn, IntPtr hMod, uint dwThreadId);
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool UnhookWindowsHookEx(IntPtr hhk);
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
      IntPtr wParam, IntPtr lParam);
    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr GetModuleHandle(string lpModuleName);
}

我这样订阅。

    MouseHook.Start();  
    MouseHook.MouseAction += new EventHandler(Event);

接收事件的函数。

   private void  Event(object sender, EventArgs e) { Console.WriteLine("Left mouse click!"); }

我将工作代码放到一个开源的nuget包中，用于用户操作挂钩。

回答：

return SetWindowsHookEx(WH_MOUSE_LL, proc, GetModuleHandle(curModule.ModuleName), 0);

当您在Windows 8之前的Windows版本的.NET

4上运行该代码时，该代码将失败。CLR不再模拟托管程序集的非托管模块句柄。您无法在代码中检测到此失败，因为它缺少必需的错误检查。都在GetModuleHandle和SetWindowsHookEx上。调用时绝对不要跳过错误检查，winapi不会抛出异常。检查他们是否返回IntPtr.Zero并在这样做时直接抛出Win32Exception。

修复很简单，SetWindowsHookEx（）需要有效的模块句柄，但在设置低级鼠标挂钩时实际上并没有使用它。因此，任何句柄都可以，您可以传递始终加载在.NET应用程序中的user32.dll的句柄。固定：

IntPtr hook = SetWindowsHookEx(WH_MOUSE_LL, proc, GetModuleHandle("user32"), 0);
if (hook == IntPtr.Zero) 
{
    throw new System.ComponentModel.Win32Exception();
}
return hook;

以上是 全局鼠标事件处理程序 的全部内容， 来源链接： utcz.com/qa/398542.html

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