键盘钩子

#region 钩子2

        [StructLayout(LayoutKind.Sequential)]
        public class KeyBoardHookStruct
        {
            public int vkCode;
            public int scanCode;
            public int flags;
            public int time;
            public int dwExtraInfo;
        }

        //委托 
        public delegate int HookProc(int nCode, int wParam, IntPtr lParam);
        static int hHook = 0;
        public const int WH_KEYBOARD_LL = 13;
        //LowLevel键盘截获，如果是WH_KEYBOARD＝2，并不能对系统键盘截取，Acrobat Reader会在你截取之前获得键盘。 
        HookProc KeyBoardHookProcedure;

        //设置钩子
        [DllImport("user32.dll")]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        //抽掉钩子
        public static extern bool UnhookWindowsHookEx(int idHook);
        [DllImport("user32.dll")]
        //调用下一个钩子
        public static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);
        [DllImport("kernel32.dll")]
        public static extern int GetCurrentThreadId();
        [DllImport("kernel32.dll")]
        public static extern IntPtr GetModuleHandle(string name);

        public int KeyBoardHookProc(int nCode, int wParam, IntPtr lParam)
        {
            if (nCode >= 0)
            {
                KeyBoardHookStruct kbh = (KeyBoardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyBoardHookStruct));
                Keys k = (Keys)Enum.Parse(typeof(Keys), kbh.vkCode.ToString());
                switch (k)
                {
                    case Keys.Tab:
                             return 1;
                }
                return CallNextHookEx(hHook, nCode, wParam, lParam);
            }
            else return 0;
        }

         public void Hook_Start()
       {
           if (hHook == 0)
           {
               KeyBoardHookProcedure = new HookProc(KeyBoardHookProc);
               hHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyBoardHookProcedure,
                       GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName), 0);
               //如果设置钩子失败. 
               if (hHook == 0)
               {
                   Hook_Clear();
               }
           }
       }
         #region 取消钩子事件
         /// <summary>
         /// 取消钩子事件
         /// </summary>
         public void Hook_Clear()
         {
             bool retKeyboard = true;
             if (hHook != 0)
             {
                 retKeyboard = UnhookWindowsHookEx(hHook);
                 hHook = 0;
             }
         }
         #endregion
        #endregion