C#如何获取鼠标点击处的控件名称？

譬如有两个button button1 和button2
button1得click事件是 button_click(object sender, EventArgs e)
button2得click事件也是 button_click(object sender, EventArgs e)

protect void button_click(object sender, EventArgs e)
{
  Button btn = (Button)sender;
  MessageBox.Show(btn.Name); 
}