一个在线考试系统出错，提示index out of range,盼高手帮忙。

Question

代码如下：
错误提示在这一行： RadioButtonList rbl = (RadioButtonList)(DataList1.Items[int_row1 - 1].FindControl("RadioButtonList1"));//核对单选题答案
            case 3:
                SqlDataAdapter myadapter3 = new SqlDataAdapter("select id,que_answer"
                    + " from tb_Questions where que_type='单选题'and que_lessonid='"
                    + dd1 + "'and que_taotiid='" + dd2 + "'order by id desc", con);
                DataSet myds3 = new DataSet();
                myadapter3.Fill(myds3);
                DataRow[] row1 = myds3.Tables[0].Select();
                //计算单选题成绩
                foreach (DataRow answer1 in row1)
                {
                    int_row1 += 1;
                    RadioButtonList rbl = (RadioButtonList)(DataList1.Items[int_row1 - 1].FindControl("RadioButtonList1"));
                    if (rbl.SelectedValue == "")
                    {
                        this.lblSel.Text = "单选题：0分";
                    }
                    else
                    {
                        if (answer1["que_answer"].ToString().Trim() == rbl.SelectedValue.ToString().Trim())
                        {
                            int_row1Point += 40 / DataList1.Items.Count;
                            this.lblSel.Text = "单选题：" + int_row1Point.ToString() + "分";
                        }
                    }
                }
                break;

Answer 1

索引越界
加个判断：
if(int_row1 < DataList1.Items.Count)
//执行...

Answer 2

数组越界啦，下标从零开始的，到达最后一个item的时候，+1 后-1就还是rowcount，就越界了

Answer 3

改成这样，还是出错。是语法错了吗？
if(int_row1 < DataList1.Items.Count)
RadioButtonList rbl = (RadioButtonList)(DataList1.Items[int_row1 - 1].FindControl("RadioButtonList1"));

Answer 4

提示：Embedded statement cannot be a  declaration or labeled statement