Asp.net嵌套数据绑定repeater主从数据嵌套

自动获取数据库中的主从关系数据，以下是获取省份及省份对应的城市，代码如下：

<asp:repeater ID="Repeater1" runat="server">
        <ItemTemplate >
            <span style ="font-weight :bold "><%#Eval ("pname") %></span>
            <ul>
                <asp:Repeater ID="detal" runat ="server" DataSource ='<%#GetCity(Eval("pid").ToString()) %>'>
                    <ItemTemplate >
                        <li><%#Eval("city_name") %></li>
                    </ItemTemplate>
                </asp:Repeater>
            </ul>
        </ItemTemplate>
    </asp:repeater>

重点：DataSource ='<%#Getawd(Eval("pid").ToString()) %>'   调用GetCity方法获取子类

protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
             BindGrid();
     }
    //获取大类的类别
    protected void BindGrid()
    {
        string cmdText = "select pid, pname from pro";
         DataTable dt = vc.GetDataTable(cmdText );
         Repeater1.DataSource = dt;
         Repeater1.DataBind();
     }
    //获取小类内容
    protected DataTable GetCity(string   id)
    {
        string cmdText = "select city_name from city where promo_id = " + id + "";
         DataTable dt = vc.GetDataTable(cmdText);
        return dt;
     }

protected void repeatTitle_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {

             DataRowView dr = (DataRowView)e.Item.DataItem;
             DataTable mydt = GetCity(dr[0].ToString());
            if (mydt.Rows.Count > 0)
            {
                 Repeater myRepeat = (Repeater)e.Item.FindControl("repeatCont");
                 myRepeat.DataSource = mydt;
                 myRepeat.DataBind();
                 mydt.Dispose();
             }
            else
            {
                 e.Item.Visible = false;  //没有数据时不显示
             }
     }