调试易

以下代码我也是从CSDN 别人回答问题时拷贝过来的，按你的要求修改了一下，供你参考：
         private void button7_Click(object sender, EventArgs e)
         {
             this.Hide();
             if (_RegisKey != null) { return; }             _RegisKey = new RegisterHotKeyClass();
             _RegisKey.Keys = Keys.Q;
             _RegisKey.ModKey =  RegisterHotKeyClass.MODKEY.MOD_ALT;
             _RegisKey.WindowHandle = this.Handle;
             _RegisKey.HotKey += new RegisterHotKeyClass.HotKeyPass(_Regis_HotKey);
             _RegisKey.StarHotKey();
         }

      private RegisterHotKeyClass _RegisKey;
         void _Regis_HotKey()
         {
             MessageBox.Show("You are pressed Alt + Q");
             
             this.Show();
             //Do something
         }
         public class RegisterHotKeyClass
         {
             private IntPtr m_WindowHandle = IntPtr.Zero;
             private MODKEY m_ModKey = MODKEY.MOD_CONTROL;
             private Keys m_Keys = Keys.A;
             private int m_WParam = 10000;
             private bool Star = false;
             private HotKeyWndProc m_HotKeyWnd = new HotKeyWndProc();             public IntPtr WindowHandle
             {
                 get { return m_WindowHandle; }
                 set { if (Star)return; m_WindowHandle = value; }
             }
             public MODKEY ModKey
             {
                 get { return m_ModKey; }
                 set { if (Star)return; m_ModKey = value; }
             }
             public Keys Keys
             {
                 get { return m_Keys; }
                 set { if (Star)return; m_Keys = value; }
             }
             public int WParam
             {
                 get { return m_WParam; }
                 set { if (Star)return; m_WParam = value; }
             }             public void StarHotKey()
             {
                 if (m_WindowHandle != IntPtr.Zero)
                 {
                     if (!RegisterHotKey(m_WindowHandle, m_WParam, m_ModKey, m_Keys))
                     {
                         throw new Exception("注册失败！");
                     }
                     try
                     {
                         m_HotKeyWnd.m_HotKeyPass = new HotKeyPass(KeyPass);
                         m_HotKeyWnd.m_WParam = m_WParam;
                         m_HotKeyWnd.AssignHandle(m_WindowHandle);
                         Star = true;
                     }
                     catch
                     {
                         StopHotKey();
                     }
                 }
             }
             private void KeyPass()
             {
                 if (HotKey != null) HotKey();
             }
             public void StopHotKey()
             {
                 if (Star)
                 {
                     if (!UnregisterHotKey(m_WindowHandle, m_WParam))
                     {
                         throw new Exception("卸载失败！");
                     }
                     Star = false;
                     m_HotKeyWnd.ReleaseHandle();
                 }
             }
             public delegate void HotKeyPass();
             public event HotKeyPass HotKey;
             private class HotKeyWndProc : NativeWindow
             {
                 public int m_WParam = 10000;
                 public HotKeyPass m_HotKeyPass;
                 protected override void WndProc(ref Message m)
                 {
                     if (m.Msg == 0x0312 && m.WParam.ToInt32() == m_WParam)
                     {
                         if (m_HotKeyPass != null) m_HotKeyPass.Invoke();
                     }                     base.WndProc(ref m);
                 }
             }             public enum MODKEY
             {
                 MOD_ALT = 0x0001,
                 MOD_CONTROL = 0x0002,
                 MOD_SHIFT = 0x0004,
                 MOD_WIN = 0x0008,
             }             [DllImport("user32.dll")]
             public static extern bool RegisterHotKey(IntPtr wnd, int id, MODKEY mode, Keys vk);             [DllImport("user32.dll")]
             public static extern bool UnregisterHotKey(IntPtr wnd, int id);         } 

private void Form1_KeyDown(object sender, KeyEventArgs e)  
  {  
  switch (e.KeyCode)  
  {  
  case Keys.Control Or Keys.A: Button2_Click(sender, e); break;  
  case Keys.B: Button4_Click(sender, e); break;  
  default:break;
  }  
  }  
钩子函数
protected override void WndProc(ref Message m)   
{   
}

 //全局按键
        void keyboardHook_KeyDown(object sender, KeyEventArgs e)
        {
           if (e.Alt&& e.KeyCode == Keys.Q)
            {
             }
         }
可到http://download.csdn.net/source/2046112下载例子

   KeyboardHook keyboardHook = new KeyboardHook();//全局按键 public frmMonitor()
        {
            InitializeComponent();
            keyboardHook.KeyDown += new KeyEventHandler(keyboardHook_KeyDown);
            keyboardHook.Start();
        }结合上面即可完成，将GlobalHook.cs和KeyboardHook.cs复制到你的项目

这里是假设在 Button 里调用，后面的代码是放在和  button7_Click 同一级的IDE 窗口中，
代码是通过了的，没有错误。至于有些有些不明白，我也一样，你不要太在乎，等你C#技术高了，再回过头来看，里面使用了属性，事件，委托 ，API，重载等等