winform程序可以做成后台监听的吗？

winform程序可以做成后台监听的吗？我想做一个类似改键的功能,时时获取键盘键入的键，比如当我敲回车键的时候我就用 SendKeys.Send("%D%D");大概就是这个意思，不知道能不能实现求大神帮忙！ --------------------编程问答-------------------- 做个钩子注入 --------------------编程问答-------------------- 怎么做啊？没做过，大哥指点一下，谢谢了 --------------------编程问答-------------------- using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Diagnostics;
using Microsoft.Win32;
using System.Windows.Forms;

namespace MyWork
{
    public class KeyboardHookLib
    {
        private const int WH_KEYBOARD_LL = 13; //键盘
        //键盘处理事件委托 ,当捕获键盘输入时调用定义该委托的方法.
        private delegate int HookHandle(int nCode, int wParam, IntPtr lParam);
        //客户端键盘处理事件
        public delegate void ProcessKeyHandle(HookStruct param, out bool handle);
        //接收 SetWindowsHookEx 返回值
        private static int _hHookValue = 0;
        //勾子程序处理事件
        private HookHandle _KeyBoardHookProcedure;
        //Hook 结构 [StructLayout(LayoutKind.Sequential)]
        public class HookStruct
        {
            public int vkCode;
            public int scanCode;
            public int flags;
            public int time;
            public int dwExtraInfo;
        }
        //设置钩子
        [DllImport("user32.dll")]
        private static extern int SetWindowsHookEx(int idHook, HookHandle lpfn, IntPtr hInstance, int threadId);
        //取消钩子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        private static extern bool UnhookWindowsHookEx(int idHook);
        //调用下一个钩子
        [DllImport("user32.dll")]
        private static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);
        //获取当前线程 ID
        [DllImport("kernel32.dll")]
        private static extern int GetCurrentThreadId(); //Gets the main module for the associated process.
        [DllImport("kernel32.dll")]
        private static extern IntPtr GetModuleHandle(string name);
        private IntPtr _hookWindowPtr = IntPtr.Zero;
        //构造器
        public KeyboardHookLib() { }
        //外部调用的键盘处理事件
        private static ProcessKeyHandle _clientMethod = null;
        /// <summary> /// 安装勾子 /// </summary>
        /// <param name="hookProcess">外部调用的键盘处理事件</param>
        public void InstallHook(ProcessKeyHandle clientMethod)
        {
            _clientMethod = clientMethod; // 安装键盘钩子
            if (_hHookValue == 0)
            {
                _KeyBoardHookProcedure = new HookHandle(OnHookProc);
                _hookWindowPtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);
                _hHookValue = SetWindowsHookEx(WH_KEYBOARD_LL, _KeyBoardHookProcedure, _hookWindowPtr, 0);
                //如果设置钩子失败.
                if (_hHookValue == 0) UninstallHook();
            }
        }
        //取消钩子事件
        public void UninstallHook()
        {
            if (_hHookValue != 0)
            {
                bool ret = UnhookWindowsHookEx(_hHookValue);
                if (ret)
                    _hHookValue = 0;
            }
        } //钩子事件内部调用,调用_clientMethod 方法转发到客户端应用。
        private static int OnHookProc(int nCode, int wParam, IntPtr lParam)
        {
            if (nCode >= 0)
            {
                //转换结构

                HookStruct hookStruct = (HookStruct)Marshal.PtrToStructure(lParam, typeof(HookStruct));      就是这有有错   未处理ArgumentException  很无奈啊！


                if (_clientMethod != null)
                {
                    bool handle = false; //调用客户提供的事件处理程序。
                    _clientMethod(hookStruct, out handle);
                    if (handle)
                        return 1; //1:表示拦截键盘,return 退出
                }
            }
            return CallNextHookEx(_hHookValue, nCode, wParam, lParam);
        }
    }
}
--------------------编程问答-------------------- 全局键盘钩子 --------------------编程问答-------------------- 可以！！！ --------------------编程问答-------------------- 那个错是怎么回事啊？没看懂...

补充：.NET技术 ,  C#