在C#项目中如何管理全局钩子

在C#项目中，可以使用全局钩子（Global Hooks）来监视和捕获系统范围内的键盘和鼠标事件

1. 首先，需要添加对System.Windows.Forms和System.Runtime.InteropServices命名空间的引用。

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

2. 定义一个类来处理全局钩子。在这个类中，我们将使用P/Invoke来调用Windows API函数。

public class GlobalHook
{
    // 定义钩子类型
    public enum HookType
    {
        WH_KEYBOARD_LL = 13,
        WH_MOUSE_LL = 14
    }

    // 定义鼠标钩子结构体
    [StructLayout(LayoutKind.Sequential)]
    public struct MouseHookStruct
    {
        public Point pt;
        public int hwnd;
        public int wHitTestCode;
        public int dwExtraInfo;
    }

    // 定义键盘钩子结构体
    [StructLayout(LayoutKind.Sequential)]
    public struct KeyboardHookStruct
    {
        public int vkCode;
        public int scanCode;
        public int flags;
        public int time;
        public int dwExtraInfo;
    }

    // 导入SetWindowsHookEx函数
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, uint dwThreadId);

    // 导入UnhookWindowsHookEx函数
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool UnhookWindowsHookEx(IntPtr hhk);

    // 导入CallNextHookEx函数
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

    // 导入GetModuleHandle函数
    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr GetModuleHandle(string lpModuleName);

    // 定义钩子回调委托
    public delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);

    // 定义钩子事件
    public event EventHandler<MouseEventArgs> MouseEvent;
    public event EventHandler<KeyEventArgs> KeyEvent;

    private IntPtr _hookID = IntPtr.Zero;
    private readonly HookProc _hookProc;

    public GlobalHook()
    {
        _hookProc = HookCallback;
    }

    // 安装钩子
    public void InstallHook(HookType hookType)
    {
        if (_hookID != IntPtr.Zero)
            return;

        IntPtr moduleHandle = GetModuleHandle(null);
        _hookID = SetWindowsHookEx((int)hookType, _hookProc, moduleHandle, 0);
    }

    // 卸载钩子
    public void UninstallHook()
    {
        if (_hookID == IntPtr.Zero)
            return;

        UnhookWindowsHookEx(_hookID);
        _hookID = IntPtr.Zero;
    }

    // 钩子回调函数
    private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
    {
        if (nCode >= 0)
        {
            if (_hookID != IntPtr.Zero)
            {
                switch ((HookType)_hookID.ToInt32())
                {
                    case HookType.WH_MOUSE_LL:
                        MouseHookStruct mouseData = (MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseHookStruct));
                        MouseEvent?.Invoke(this, new MouseEventArgs(mouseData.pt));
                        break;

                    case HookType.WH_KEYBOARD_LL:
                        KeyboardHookStruct keyData = (KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
                        KeyEvent?.Invoke(this, new KeyEventArgs(keyData.vkCode));
                        break;
                }
            }
        }

        return CallNextHookEx(_hookID, nCode, wParam, lParam);
    }
}

3. 在你的应用程序中使用GlobalHook类来监听键盘和鼠标事件。

public partial class MainForm : Form
{
    private readonly GlobalHook _globalHook;

    public MainForm()
    {
        InitializeComponent();

        _globalHook = new GlobalHook();
        _globalHook.MouseEvent += OnMouseEvent;
        _globalHook.KeyEvent += OnKeyEvent;
    }

    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);

        // 安装钩子
        _globalHook.InstallHook(GlobalHook.HookType.WH_MOUSE_LL);
        _globalHook.InstallHook(GlobalHook.HookType.WH_KEYBOARD_LL);
    }

    protected override void OnClosed(EventArgs e)
    {
        base.OnClosed(e);

        // 卸载钩子
        _globalHook.UninstallHook();
    }

    private void OnMouseEvent(object sender, MouseEventArgs e)
    {
        Console.WriteLine($"Mouse event: {e.Location}");
    }

    private void OnKeyEvent(object sender, KeyEventArgs e)
    {
        Console.WriteLine($"Key event: {e.KeyValue}");
    }
}

这样，你就可以在C#项目中使用全局钩子来监视和捕获系统范围内的键盘和鼠标事件了。请注意，全局钩子可能会影响系统性能，因此在不需要时，务必及时卸载钩子。