repeater取RadioButtonList 的问题

[lhetiger]

用.net 后台cs生成如下RadioButtonList 放在repeater里面。
RadioButtonList rblControl = new RadioButtonList();
rblControl.ID = "field_control_" + modelt.id.ToString();
rblControl.RepeatDirection = RepeatDirection.Horizontal;
rblControl.RepeatLayout = RepeatLayout.Flow;
HtmlGenericControl htmlDiv2 = new HtmlGenericControl("div");
htmlDiv2.Attributes.Add("class", "rule-multi-radio");
htmlDiv2.Controls.Add(rblControl);
但用下面代码取不到值。是哪有问题的呢
string rblControl = ((RadioButtonList)rptList1.Items[chosevalue].FindControl("field_control_" + dr["id"].ToString())).SelectedValue;


请教各位大神。谢谢！