试图以编程方式设置RadioButtonList的事件

Question

在页面加载时使用RadioButtonList()类创建了一组单选按钮，在尝试设置控件的事件OnSelectedIndexChanged时，但是Visual Studio和页面测试都给了我以下错误:

System.Web.UI.WebControls.ListControl。受保护的可重写潜艇OnSelectedIndexChanged(如System.EventArgs)在因为它是"Protected"。

为什么不能以编程方式访问此控件的此事件并告诉我它是Protected ?

这是代码:

Sub Page_Load(Sender As Object, E As EventArgs)                        
       Dim group_answers As New RadioButtonList()
       group_answers.AutoPostBack = True
       AddHandler group_answers.OnSelectedIndexChanged, AddressOf check_selection
       group_answers.Items.Add(New ListItem("0%", "17"))
       group_answers.Items.Add(New ListItem("10%", "18"))
       group_answers.Items.Add(New ListItem("20%", "19"))
       group_answers.Items.Add(New ListItem("30%", "20"))                                              
       group_answers.RepeatDirection = RepeatDirection.Horizontal                            
       question_answer.Controls.Add(group_answers)    
End Sub

Answer 1

我想你想订阅SelectedIndexChanged事件:

AddHandler group_answers.SelectedIndexChanged, AddressOf check_selection