sender对象简单应用(按钮)

页面有5个Button，Every Button的Click事件都指定为btnclick

 protected void btnclick(object sender, EventArgs e)
    {
        Button ClickButton = (Button)sender;
        switch (ClickButton.ID)
        {
            case "Button1":
                ClickButton.BackColor = System.Drawing.Color.Yellow;
                break;
            case "Button2":
                ClickButton.BackColor = System.Drawing.Color.Red;
                break;
            case "Button3":
                ClickButton.BackColor = System.Drawing.Color.RoyalBlue;
                break;
            case "Button4":
                ClickButton.BackColor = System.Drawing.Color.SeaGreen;
                break;
            case "Button5":
                ClickButton.BackColor = System.Drawing.Color.Goldenrod;
                break;
        }
    }

点击各个Button执行结果：（如图）