42

我有以下代码，我从某处获得来捕获鼠标事件。我修改了它并制作了一个事件处理程序，以便我可以订阅它。鼠标事件被正确捕获。但它永远不会触发事件处理程序。任何人都可以弄清楚代码有什么问题吗？

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, flags, 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);
}

我像这样订阅它。

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!");

更新： 我将工作代码放在一个开源 nuget 包中，用于用户操作挂钩。

4

3 回答 3

37 
return SetWindowsHookEx(WH_MOUSE_LL, proc, GetModuleHandle(curModule.ModuleName), 0);

当您在早于 Windows 8 的 Windows 版本上的 .NET 4 上运行此代码时，此代码将失败。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故障，因为它缺少所需的错误检查。在 GetModuleHandle 和 SetWindowsHookEx 上。pinvoke 时不要跳过错误检查，winapi 不会抛出异常。检查它们是否返回 IntPtr.Zero 并在返回时简单地抛出 Win32Exception。

修复很简单，SetWindowsHookEx() 需要一个有效的模块句柄，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 user32.dll 的句柄，该句柄始终加载在 .NET 应用程序中。使固定：

IntPtr hook = SetWindowsHookEx(WH_MOUSE_LL, proc, GetModuleHandle("user32"), 0);
if (hook == IntPtr.Zero) 
{
    throw new System.ComponentModel.Win32Exception();
}
return hook;
于 2012-07-23T15:14:42.363 回答
11

我只是将您的代码复制到一个简单的 Windows 窗体中，并且它的工作方式与您描述的一样。你是如何使用它的？你在哪里开始和附加活动？

为了完整起见，这是我最终得到的代码 - 从一个简单的 C# 表单模板开始

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

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

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

    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);


    }
}
于 2012-07-23T07:38:04.603 回答
3

对于任何未来的访客：

我已经实现了一个线程级鼠标钩子。

在此处输入图像描述

_process = Process.Start(@"c:\windows\notepad.exe");
//_process = Process.Start(@"c:\windows\syswow64\notepad.exe"); // works also with 32-bit

_mouseHook = new MouseHook(_process.Id);
_mouseHook.MessageReceived += MouseHook_MessageReceived;
_mouseHook.Install();

...

private void MouseHook_MessageReceived(object sender, MouseMessageEventArgs e)
{
    Debug.WriteLine($"Mouse Message Code: {e.MessageCode}; X: {e.X}; Y: {e.Y}; Delta: {e.Delta}");
}
于 2020-05-19T14:42:06.520 回答