c# - 如何在 Linux 中使用 C# 创建全局键盘挂钩

在这里回答我自己的问题，因为我必须为此做很多研究，我相信它会在以后对其他人有所帮助。我选择了选项 1，因为它似乎是最容易实现的。

警告 - 这篇文章中会有很多代码

概括

出于我的意图和目的，我希望有一些代码可以在用户按下系统任意位置的键时发布事件。在开发这个时，我发现我也可以挂钩鼠标事件。

需要注意的是，这里的代码像 linux OS 并没有真正区分键盘按钮按下和鼠标按钮按下。对于 linux，它们都只是按钮。

了解您实际上可以扩展此代码以使用其他项目，如游戏手柄和特殊输入外围设备，如果您愿意。

附加问题 - 如问题所述，此代码不会阻止设备输入到其他程序。如果您想覆盖电源按钮或音量按钮的默认功能，这可能会出现问题。

设置权限

为了运行此代码，运行此程序的用户必须在输入用户组中，否则将引发异常。运行此代码以将当前用户添加到该组。

 sudo gpasswd -a $USER input

事件类型.cs

由于文件夹 /dev/input 本质上是 linux 操作系统的一堆输入/输出设备的事件总线，因此您可能想要使用多种事件类型。这是我能够组合在一起的枚举，以使破译事件类型更容易一些。

public enum EventType
{
    /// <summary>
    /// Used as markers to separate events. Events may be separated in time or in space, such as with the multitouch protocol.
    /// </summary>
    EV_SYN,

    /// <summary>
    /// Used to describe state changes of keyboards, buttons, or other key-like devices.
    /// </summary>
    EV_KEY,

    /// <summary>
    /// Used to describe relative axis value changes, e.g. moving the mouse 5 units to the left.
    /// </summary>
    EV_REL,

    /// <summary>
    /// Used to describe absolute axis value changes, e.g. describing the coordinates of a touch on a touchscreen.
    /// </summary>
    EV_ABS,

    /// <summary>
    /// Used to describe miscellaneous input data that do not fit into other types.
    /// </summary>
    EV_MSC,

    /// <summary>
    /// Used to describe binary state input switches.
    /// </summary>
    EV_SW,

    /// <summary>
    /// Used to turn LEDs on devices on and off.
    /// </summary>
    EV_LED,

    /// <summary>
    /// Used to output sound to devices.
    /// </summary>
    EV_SND,

    /// <summary>
    /// Used for autorepeating devices.
    /// </summary>
    EV_REP,

    /// <summary>
    /// Used to send force feedback commands to an input device.
    /// </summary>
    EV_FF,

    /// <summary>
    /// A special type for power button and switch input.
    /// </summary>
    EV_PWR,

    /// <summary>
    /// Used to receive force feedback device status.
    /// </summary>
    EV_FF_STATUS,
}

KeyState.cs

与许多其他事件处理系统一样，每次用户按键时都会发生多个事件。一次是按下键时，一次是按下键时，另一次是用户决定按住键时。

public enum KeyState
{
    KeyUp,
    KeyDown,
    KeyHold
}

事件代码.cs

每个不同的按钮都与一个事件代码相关联。无论是键盘上的按钮还是鼠标上的按钮，您都可以在这里找到它。他是一个帮助枚举类，可以更容易地破译这些代码。

/// <summary>
/// Mapping for this can be found here: https://github.com/torvalds/linux/blob/master/include/uapi/linux/input-event-codes.h
/// </summary>
public enum EventCode
{
    Reserved = 0,
    Esc = 1,
    Num1 = 2,
    Num2 = 3,
    Num3 = 4,
    Num4 = 5,
    Num5 = 6,
    Num6 = 7,
    Num7 = 8,
    Num8 = 9,
    Num9 = 10,
    Num0 = 11,
    Minus = 12,
    Equal = 13,
    Backspace = 14,
    Tab = 15,
    Q = 16,
    W = 17,
    E = 18,
    R = 19,
    T = 20,
    Y = 21,
    U = 22,
    I = 23,
    O = 24,
    P = 25,
    LeftBrace = 26,
    RightBrace = 27,
    Enter = 28,
    LeftCtrl = 29,
    A = 30,
    S = 31,
    D = 32,
    F = 33,
    G = 34,
    H = 35,
    J = 36,
    K = 37,
    L = 38,
    Semicolon = 39,
    Apostrophe = 40,
    Grave = 41,
    LeftShift = 42,
    Backslash = 43,
    Z = 44,
    X = 45,
    C = 46,
    V = 47,
    B = 48,
    N = 49,
    M = 50,
    Comma = 51,
    Dot = 52,
    Slash = 53,
    RightShift = 54,
    KpAsterisk = 55,
    LeftAlt = 56,
    Space = 57,
    Capslock = 58,
    F1 = 59,
    Pf2 = 60,
    F3 = 61,
    F4 = 62,
    F5 = 63,
    F6 = 64,
    F7 = 65,
    F8 = 66,
    Pf9 = 67,
    F10 = 68,
    Numlock = 69,
    ScrollLock = 70,
    Kp7 = 71,
    Kp8 = 72,
    Kp9 = 73,
    PkpMinus = 74,
    Kp4 = 75,
    Kp5 = 76,
    Kp6 = 77,
    KpPlus = 78,
    Kp1 = 79,
    Kp2 = 80,
    Kp3 = 81,
    Kp0 = 82,
    KpDot = 83,

    Zenkakuhankaku = 85,
    //102ND = 86,
    F11 = 87,
    F12 = 88,
    Ro = 89,
    Katakana = 90,
    Hiragana = 91,
    Henkan = 92,
    Katakanahiragana = 93,
    Muhenkan = 94,
    KpJpComma = 95,
    KpEnter = 96,
    RightCtrl = 97,
    KpSlash = 98,
    SysRq = 99,
    RightAlt = 100,
    LineFeed = 101,
    Home = 102,
    Up = 103,
    Pageup = 104,
    Left = 105,
    Right = 106,
    End = 107,
    Down = 108,
    Pagedown = 109,
    Insert = 110,
    Delete = 111,
    Macro = 112,
    Mute = 113,
    VolumeDown = 114,
    VolumeUp = 115,
    Power = 116, // SC System Power Down
    KpEqual = 117,
    KpPlusMinus = 118,
    Pause = 119,
    Scale = 120, // AL Compiz Scale (Expose)

    KpComma = 121,
    Hangeul = 122,
    Hanja = 123,
    Yen = 124,
    LeftMeta = 125,
    RightMeta = 126,
    Compose = 127,

    Stop = 128, // AC Stop
    Again = 129,
    Props = 130, // AC Properties
    Undo = 131, // AC Undo
    Front = 132,
    Copy = 133, // AC Copy
    Open = 134, // AC Open
    Paste = 135, // AC Paste
    Find = 136, // AC Search
    Cut = 137, // AC Cut
    Help = 138, // AL Integrated Help Center
    Menu = 139, // Menu (show menu)
    Calc = 140, // AL Calculator
    Setup = 141,
    Sleep = 142, // SC System Sleep
    Wakeup = 143, // System Wake Up
    File = 144, // AL Local Machine Browser
    Sendfile = 145,
    DeleteFile = 146,
    Xfer = 147,
    Prog1 = 148,
    Prog2 = 149,
    Www = 150, // AL Internet Browser
    MsDos = 151,
    Coffee = 152, // AL Terminal Lock/Screensaver
    RotateDisplay = 153, // Display orientation for e.g. tablets
    CycleWindows = 154,
    Mail = 155,
    Bookmarks = 156, // AC Bookmarks
    Computer = 157,
    Back = 158, // AC Back
    Forward = 159, // AC Forward
    CloseCd = 160,
    EjectCd = 161,
    EjectCloseCd = 162,
    NextSong = 163,
    PlayPause = 164,
    PreviousSong = 165,
    StopCd = 166,
    Record = 167,
    Rewind = 168,
    Phone = 169, // Media Select Telephone
    Iso = 170,
    Config = 171, // AL Consumer Control Configuration
    Homepage = 172, // AC Home
    Refresh = 173, // AC Refresh
    Exit = 174, // AC Exit
    Move = 175,
    Edit = 176,
    ScrollUp = 177,
    ScrollDown = 178,
    KpLeftParen = 179,
    KpRightParen = 180,
    New = 181, // AC New
    Redo = 182, // AC Redo/Repeat
    
    F13 = 183,
    F14 = 184,
    F15 = 185,
    F16 = 186,
    F17 = 187,
    F18 = 188,
    F19 = 189,
    F20 = 190,
    F21 = 191,
    F22 = 192,
    F23 = 193,
    F24 = 194,
    
    PlayCd = 200,
    PauseCd = 201,
    Prog3 = 202,
    Prog4 = 203,
    Dashboard = 204,    // AL Dashboard
    Suspend = 205,
    Close = 206,    // AC Close
    Play = 207,
    FastForward = 208,
    BassBoost = 209,
    Print = 210,    // AC Print
    Hp = 211,
    Camera = 212,
    Sound = 213,
    Question = 214,
    Email = 215,
    Chat = 216,
    Search = 217,
    Connect = 218,
    Finance = 219,  // AL Checkbook/Finance
    Sport = 220,
    Shop = 221,
    AltErase = 222,
    Cancel = 223,   // AC Cancel
    BrightnessDown = 224,
    BrightnessUp = 225,
    Media = 226,
    
    SwitchVideoMode = 227,  // Cycle between available video outputs (Monitor/LCD/TV-out/etc)
    KbdIllumToggle = 228,
    KbdIllumDown = 229,
    KbdIllumUp = 230,

    Send = 231, // AC Send
    Reply = 232,    // AC Reply
    ForwardMail = 233,  // AC Forward Msg
    Save = 234, // AC Save
    Documents = 235,

    Battery = 236,

    Bluetooth = 237,
    Wlan = 238,
    Uwb = 239,

    Unknown = 240,

    VideoNext = 241,    // drive next video source
    VideoPrev = 242,    // drive previous video source
    BrightnessCycle = 243,  // brightness up, after max is min
    BrightnessAuto = 244,   // Set Auto Brightness: manual brightness control is off, rely on ambient
    DisplayOff = 245,   // display device to off state

    Wwan = 246, // Wireless WAN (LTE, UMTS, GSM, etc.)
    RfKill = 247,   // Key that controls all radios

    MicMute = 248,  // Mute / unmute the microphone
    LeftMouse = 272,
    RightMouse = 273,
    MiddleMouse = 274,
    MouseBack = 275,
    MouseForward = 276,
    
    ToolFinger = 325,
    ToolQuintTap = 328,
    Touch = 330,
    ToolDoubleTap = 333, 
    ToolTripleTap = 334, 
    ToolQuadTap = 335,
    Mic = 582
}

鼠标轴.cs

鼠标移动以移动量和与该变化相关的轴来表示。0 代表 X 轴上的移动，1 代表 Y 轴上的移动。

public enum MouseAxis
{
    X,
    Y
}

KeypressEvent.cs

这是我用来处理按键事件的事件。

public class KeyPressEvent : EventArgs
{
    public KeyPressEvent(EventCode code, KeyState state)
    {
        Code = code;
        State = state;
    }

    public EventCode Code { get; }
    
    public KeyState State { get; }
}

鼠标移动事件.cs

这是我使用进程鼠标移动更改更新的事件。

public class MouseMoveEvent : EventArgs
{
    public MouseMoveEvent(MouseAxis axis, int amount)
    {
        Axis = axis;
        Amount = amount;
    }
    
    public MouseAxis Axis { get; }
    
    public int Amount { get; set; }
}

输入阅读器.cs

这是大部分工作发生的地方。在这里，我们有一个类，您可以在其中提供一个事件文件的路径，并在它进入时发布更新。执行此操作的示例文件是“/dev/input/event0”。

需要更多的研究来支持更多的事件类型，但我只对键盘和鼠标输入感兴趣，所以它符合我的目的。我还选择删除每个按钮事件中包含的时间戳，但如果您有兴趣，可以在缓冲区的前 16 位上找到它。

public class InputReader : IDisposable
{
    public delegate void RaiseKeyPress(KeyPressEvent e);

    public delegate void RaiseMouseMove(MouseMoveEvent e);

    public event RaiseKeyPress OnKeyPress;
    public event RaiseMouseMove OnMouseMove;

    private const int BufferLength = 24;
    
    private readonly byte[] _buffer = new byte[BufferLength];
    
    private FileStream _stream;
    private bool _disposing;

    public InputReader(string path)
    {
        _stream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

        Task.Run(Run);
    }

    private void Run()
    {
        while (true)
        {
            if (_disposing)
                break;

            _stream.Read(_buffer, 0, BufferLength);

            var type = BitConverter.ToInt16(new[] {_buffer[16], _buffer[17]}, 0);
            var code = BitConverter.ToInt16(new[] {_buffer[18], _buffer[19]}, 0);
            var value = BitConverter.ToInt32(new[] {_buffer[20], _buffer[21], _buffer[22], _buffer[23]}, 0);

            var eventType = (EventType) type;

            switch (eventType)
            {
                case EventType.EV_KEY:
                    HandleKeyPressEvent(code, value);
                    break;
                case EventType.EV_REL:
                    var axis = (MouseAxis) code;
                    var e = new MouseMoveEvent(axis, value);
                    OnMouseMove?.Invoke(e);
                    break;
            }
        }
    }

    private void HandleKeyPressEvent(short code, int value)
    {
        var c = (EventCode) code;
        var s = (KeyState) value;
        var e = new KeyPressEvent(c, s);
        OnKeyPress?.Invoke(e);
    }

    public void Dispose()
    {
        _disposing = true;
        _stream.Dispose();
        _stream = null;
    }
}

聚合输入读取器.cs

由于我希望处理来自系统上任何位置的每个设备的输入，因此我将这些类放在一起以聚合来自“/dev/input”文件夹中所有文件的输入事件。

已知问题- 如果 USB 设备在运行时被移除，此代码将引发异常。我确实打算在我自己的应用程序实现中修复它，但我现在没有时间处理它。

public class AggregateInputReader : IDisposable
{
    private List<InputReader> _readers = new();
    
    public event InputReader.RaiseKeyPress OnKeyPress;

    public AggregateInputReader()
    {
        var files = Directory.GetFiles("/dev/input/", "event*");

        foreach (var file in files)
        {
            var reader = new InputReader(file);
            
            reader.OnKeyPress += ReaderOnOnKeyPress;

            _readers.Add(reader);
        }
    }

    private void ReaderOnOnKeyPress(KeyPressEvent e)
    {
        OnKeyPress?.Invoke(e);
    }

    public void Dispose()
    {
        foreach (var d in _readers)
        {
            d.OnKeyPress -= ReaderOnOnKeyPress;
            d.Dispose();
        }

        _readers = null;
    }
}

示例用法

现在可以用两行代码来完成，这还不错。

public class Program
{
    public static void Main(string[] args)
    {
        using var aggHandler = new AggregateInputReader();

        aggHandler.OnKeyPress += (e) => { System.Console.WriteLine($"Code:{e.Code} State:{e.State}"); };

        System.Console.ReadLine();
    }
}

感谢您坚持这一点。我希望它对你有用！