求助，Panel 里的 CheckedChanged 事件为什么无响应？

[as809830]

foreach (ti li in listTi)
{
Label lbl = new Label();
lbl.Text = li.tiMu;
panel.Controls.Add(lbl);
panel.Controls.Add(new LiteralControl("<br/>"));
for (char i = 'A'; li.daAn.IndexOf("+") != -1; i++)
{
string getString = li.daAn.Substring(0, li.daAn.IndexOf("+"));
int stringLength = getString.Length + 1;
li.daAn = li.daAn.Substring(stringLength, li.daAn.Length - stringLength);
RadioButton rb = new RadioButton();
rb.ID = li.id.ToString() + i;
rb.Text = getString;
rb.GroupName = "gn" + li.id;
rb.CheckedChanged += new EventHandler(rb_CheckedChanged);
panel.Controls.Add(rb);
panel.Controls.Add(new LiteralControl("<br/>"));


}
}
}
void rb_CheckedChanged(object sender, EventArgs e)
{
//无响应
}

[阿非]

在 Page_load 中写添加控件的代码