【实践】object最形象的例子

    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void lblDoubleClick_Click(object sender, EventArgs e)
        {
            //这种写法不能复用，写死了lblDouble.text值会改变。如果其他lable.click要调用的话,
            //还是只有lbldouble.text值产生变化。要的是不管哪里调用都是当前的label值变化
            //lblDoubleClick.Text = "点击了"; 

            Label a = (Label)sender;
            a.Text = "点击了";
        }

    }