C#中注册热键

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


namespace Gkill
{
    class RegistHotkey
    {
        IntPtr hwnd;
        //获取窗口句柄
        [DllImport("user32.dll", EntryPoint = "FindWindow")]
        private extern static IntPtr FindWindow(string lpClassName, string lpWindowName);
        //注册全局热键
        [DllImport("user32.dll")]
        private static extern int RegisterHotKey(IntPtr hwnd, int id, int fsModifiers, int vk);
        //删除全局热键
        [DllImport("user32.dll")]
        private static extern int UnregisterHotKey(IntPtr hwnd, int id);

        private const int WM_HOTKEY = 0x312; //窗口消息-热键
        private const int WM_CREATE = 0x1; //窗口消息-创建
        private const int WM_DESTROY = 0x2; //窗口消息-销毁
        private const int MOD_ALT = 0x1; //ALT
        private const int MOD_CONTROL = 0x2; //CTRL
        private const int MOD_SHIFT = 0x4; //SHIFT
        private const int VK_SPACE = 0x20; //SPACE
    
        public RegistHotkey()
        {
            hwnd = FindWindow(null,"Gki");
        }
        public bool RegKey(int id, int fsModifiers, int vk)
        {
            if (RegisterHotKey(hwnd, id, fsModifiers, vk) == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
        public bool UnRegKey(int id)
        {
            if (UnregisterHotKey(hwnd, id) == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
    }
}

 private void RegistHotKey()
        {
            RegistHotkey hotkey = new RegistHotkey();
            //displayHotkey
            hotkey.RegKey(100, 0x2, (int)Keys.O);
            //hideHotkey
            hotkey.RegKey(200, 0x2, (int)Keys.P);

        }
        protected override void WndProc(ref Message m)
        {
            switch (m.Msg)
            {
                case 0x312://WM_HOTKEY:0x312
                    MessageBox.Show("有热键按下！但不知道是谁");
                    switch (m.WParam.ToInt32())
                    {
                        case (100):
                            this.Visible=true;
                            this.Activate();
                            break;
                         case (200):
                            this.Visible = false;
                            break;
                        default:
                            break;
                    }
                    break;

                case 0x1://WM_CREATE:0x1
                    break;

                case 0x2://WM_DESTROY:0x2
                    break;
            }
            base.WndProc(ref m); //将系统消息传递自父类的WndProc
        }