自己编的小程序“非爱不可”，有个奇怪的小问题
”非爱不可“就是有2个按钮，1个按钮是“爱”，1个是“不爱”，让别人选，一旦鼠标移到“不爱”处，按钮会离开鼠标，让对方无法点到

我拉了2个按钮，爱用btnlove，不爱用btnnlove
下面是我写的鼠标移动到“不爱”按钮时的代码，可以运行，运行开始的时候很好，试验的次数多了后，会有偶尔”不爱“按钮一部分或者全部跑到窗口边界下面的现象，可我明明让“不爱”按钮的TOP在窗口高度减按钮高度之间随机，不应该出现越界的现象，为什么还会出下界？而且我为了不让它出下界，还加了一句IF来验证，可运行程序了仍然会出下界。好奇怪哦，哪位大哥能帮帮我，谢谢
private void btnnlove_MouseMove(object sender, MouseEventArgs e)
{
  Random r = new Random();
  btnnlove.Top = r.Next(this.Height - btnnlove.Height);
  btnnlove.Left= r.Next(this.Width - btnnlove.Width);

  //验证按钮“不爱”是否覆盖按钮“爱”，如果覆盖，重新随机
  bool check = btnnlove.Location.X >= (btnlove.Location.X - btnlove.Width) && btnnlove.Location.X <= (btnlove.Location.X + btnlove.Width) && btnnlove.Location.Y >= (btnlove.Location.Y - btnlove.Height) && btnnlove.Location.Y <= (btnlove.Location.Y + btnlove.Height);
  //出问题后加的这句，想避免出下界的问题
  if (btnnlove.Location.Y >= (this.Height - btnnlove.Height)) check = true;
  while(check)
  {
  btnnlove.Top = r.Next(this.Height - btnnlove.Height);
  btnnlove.Left = r.Next(this.Width - btnnlove.Width);
  check = btnnlove.Location.X >= (btnlove.Location.X - btnlove.Width) && btnnlove.Location.X <= (btnlove.Location.X + btnlove.Width) && btnnlove.Location.Y >= (btnlove.Location.Y - btnlove.Height) && btnnlove.Location.Y <= (btnlove.Location.Y + btnlove.Height);
  //出问题后加的这句，想避免出下界的问题
  if (btnnlove.Location.Y >= (this.Height - btnnlove.Height)) check = true;
  }
 }

------解决方案--------------------
好象btnnlove.Top = r.Next(this.Height - btnnlove.Height); 
中的this.Height的大小包括标题栏
------解决方案--------------------
楼上正解，把this.Height改成this.ClientSize.Height就可以了