知识点

捕获键盘按键可以重载该函数实现：

//捕获方向键按下

protected override bool IsInputKey(Keys keyData)
 {
     if (keyData == Keys.Up || keyData == Keys.Down || keyData == Keys.Left || keyData == Keys.Right)
                return true;
      else
                return base.IsInputKey(keyData);
   }