c# console 程序实现 hot key

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace ConsoleApplication1
{
    /// <summary>
    /// A class that manages a global low level keyboard hook
    /// </summary>
    class globalKeyboardHook
    {
        #region Constant, Structure and Delegate Definitions
        /// <summary>
        /// defines the callback type for the hook
        /// </summary>
        public delegate int keyboardHookProc(int code, int wParam, ref keyboardHookStruct lParam);

        public struct keyboardHookStruct
        {
            public int vkCode;
            public int scanCode;
            public int flags;
            public int time;
            public int dwExtraInfo;
        }

        const int WH_KEYBOARD_LL = 13;
        const int WM_KEYDOWN = 0x100;
        const int WM_KEYUP = 0x101;
        const int WM_SYSKEYDOWN = 0x104;
        const int WM_SYSKEYUP = 0x105;
        #endregion

        keyboardHookProc khp;

        #region Instance Variables
        /// <summary>
        /// The collections of keys to watch for
        /// </summary>
        public List<int> HookedKeys = new List<int>();
        /// <summary>
        /// Handle to the hook, need this to unhook and call the next hook
        /// </summary>
        IntPtr hhook = IntPtr.Zero;
        #endregion

        #region Events
        /// <summary>
        /// Occurs when one of the hooked keys is pressed
        /// </summary>
        public event EventHandler<KeyDownUpEventArgs> KeyDown;
        /// <summary>
        /// Occurs when one of the hooked keys is released
        /// </summary>
        public event EventHandler<KeyDownUpEventArgs> KeyUp;
        #endregion

        #region Constructors and Destructors
        /// <summary>
        /// Initializes a new instance of the <see cref="globalKeyboardHook"/> class and installs the keyboard hook.
        /// </summary>
        public globalKeyboardHook()
        {
            khp = new keyboardHookProc(hookProc);
            hook();
        }

        /// <summary>
        /// Releases unmanaged resources and performs other cleanup operations before the
        /// <see cref="globalKeyboardHook"/> is reclaimed by garbage collection and uninstalls the keyboard hook.
        /// </summary>
        ~globalKeyboardHook()
        {
            unhook();
        }
        #endregion

        #region Public Methods
        /// <summary>
        /// Installs the global hook
        /// </summary>
        public void hook()
        {
            IntPtr hInstance = LoadLibrary("User32");
            hhook = SetWindowsHookEx(WH_KEYBOARD_LL, khp, hInstance, 0);
        }

        /// <summary>
        /// Uninstalls the global hook
        /// </summary>
        public void unhook()
        {
            UnhookWindowsHookEx(hhook);
        }

        /// <summary>
        /// The callback for the keyboard hook
        /// </summary>
        /// <param name="code">The hook code, if it isn't >= 0, the function shouldn't do anyting</param>
        /// <param name="wParam">The event type</param>
        /// <param name="lParam">The keyhook event information</param>
        /// <returns></returns>
        public int hookProc(int code, int wParam, ref keyboardHookStruct lParam)
        {
            if (code >= 0)
            {
                var key = new KeyDownUpEventArgs(lParam.vkCode);
                if (HookedKeys.Contains(key.KeyCode))
                {
                    if ((wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN) && (KeyDown != null))
                    {
                        KeyDown(this, key);
                    }
                    else if ((wParam == WM_KEYUP || wParam == WM_SYSKEYUP) && (KeyUp != null))
                    {
                        KeyUp(this, key);
                    }
                    if (key.Handled)
                        return 1;
                }
            }
            return CallNextHookEx(hhook, code, wParam, ref lParam);
        }
        #endregion

        #region DLL imports
        /// <summary>
        /// Sets the windows hook, do the desired event, one of hInstance or threadId must be non-null
        /// </summary>
        /// <param name="idHook">The id of the event you want to hook</param>
        /// <param name="callback">The callback.</param>
        /// <param name="hInstance">The handle you want to attach the event to, can be null</param>
        /// <param name="threadId">The thread you want to attach the event to, can be null</param>
        /// <returns>a handle to the desired hook</returns>
        [DllImport("user32.dll")]
        static extern IntPtr SetWindowsHookEx(int idHook, keyboardHookProc callback, IntPtr hInstance, uint threadId);

        /// <summary>
        /// Unhooks the windows hook.
        /// </summary>
        /// <param name="hInstance">The hook handle that was returned from SetWindowsHookEx</param>
        /// <returns>True if successful, false otherwise</returns>
        [DllImport("user32.dll")]
        static extern bool UnhookWindowsHookEx(IntPtr hInstance);

        /// <summary>
        /// Calls the next hook.
        /// </summary>
        /// <param name="idHook">The hook id</param>
        /// <param name="nCode">The hook code</param>
        /// <param name="wParam">The wparam.</param>
        /// <param name="lParam">The lparam.</param>
        /// <returns></returns>
        [DllImport("user32.dll")]
        static extern int CallNextHookEx(IntPtr idHook, int nCode, int wParam, ref keyboardHookStruct lParam);

        /// <summary>
        /// Loads the library.
        /// </summary>
        /// <param name="lpFileName">Name of the library</param>
        /// <returns>A handle to the library</returns>
        [DllImport("kernel32.dll")]
        static extern IntPtr LoadLibrary(string lpFileName);
        #endregion
    }

    public class KeyDownUpEventArgs : EventArgs
    {
        public KeyDownUpEventArgs(int keyCode)
        {
            this.KeyCode = keyCode;
        }

        public int KeyCode { get; private set; }
        public bool Handled { get; set; }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace ConsoleApplication1
{
    public class Win32APIs
    {
        [DllImport("user32", EntryPoint = "GetMessage")]
        public static extern int GetMessage(
                out tagMSG lpMsg,
                int hwnd,
                int wMsgFilterMin,
                int wMsgFilterMax
        );

        [DllImport("user32", EntryPoint = "DispatchMessage")]
        public static extern int DispatchMessage(
               ref tagMSG lpMsg
        );

        [DllImport("user32", EntryPoint = "TranslateMessage")]
        public static extern int TranslateMessage(
               ref tagMSG lpMsg
        );

    }

    public struct tagMSG
    {
        public int hwnd;
        public uint message;
        public int wParam;
        public long lParam;
        public uint time;
        public int pt;
    }

}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Security.Principal;
using System.Runtime.InteropServices;
using System.IO;
namespace ConsoleApplication1
{
    static class Program
    {
        static void Main(string[] args)
        {
            globalKeyboardHook gkh = new globalKeyboardHook();
            gkh.HookedKeys.Add((int)'A');
            gkh.HookedKeys.Add((int)'B');
            gkh.KeyDown += new EventHandler<KeyDownUpEventArgs>(gkh_KeyDown);
            gkh.KeyUp += new EventHandler<KeyDownUpEventArgs>(gkh_KeyUp);

            int bRet;
            tagMSG msg;
            int hWnd = 0;

            while ((bRet = Win32APIs.GetMessage(out msg, hWnd, 0, 0)) != 0)
            {
                if (bRet == -1)
                {
                    // handle the error and possibly exit
                }
                else
                {
                    Win32APIs.TranslateMessage(ref msg);
                    Win32APIs.DispatchMessage(ref msg);
                }
            }   
        }

        static void gkh_KeyUp(object sender, KeyDownUpEventArgs e)
        {
            Console.WriteLine(string.Format("{0} up", (char)e.KeyCode));
        }

        static void gkh_KeyDown(object sender, KeyDownUpEventArgs e)
        {
            Console.WriteLine(string.Format("{0} down", (char)e.KeyCode));
        }
    }
}