gridview中dropdownlist的selectvalue问题 急

gridview已经绑定数据，其中有一列使用模板，模板中添加dropdownlist控件也绑定了数据。在page_load的时候给dropdownlist选中值，值是从gridview的数据源中得来的如何操作？

<asp:GridView ID="gridviewcd" runat="server" AutoGenerateColumns="False"  PageSize="20"
            CellPadding="4" DataSourceID="ds" ForeColor="#333333" GridLines="None" 
            AllowPaging="True" AllowSorting="True" >
            <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
            <Columns>
                <asp:BoundField DataField="id" HeaderText="序号" InsertVisible="False" 
                    ReadOnly="True" SortExpression="id" />
                <asp:HyperLinkField DataNavigateUrlFields="id" 
                    DataNavigateUrlFormatString="customerdetail.aspx?id={0}" 
                    DataTextField="imoAccount" HeaderText="imo号" 
                    NavigateUrl="~/web/customerdetail.aspx" SortExpression="imoAccount" 
                    Target="mainframe" />
                
                <asp:BoundField DataField="companyName" HeaderText="名称" 
                    SortExpression="companyName" />
                <asp:BoundField DataField="customerStatus" HeaderText="状态" 
                    SortExpression="customerStatus" />
                <asp:BoundField DataField="buyNum" HeaderText="购买条数" 
                    SortExpression="buyNum" />
                <asp:BoundField DataField="organizationNum" HeaderText="组织架构数" 
                    SortExpression="organizationNum" />
                <asp:BoundField DataField="onlineNum" HeaderText="人数" 
                    SortExpression="onlineNum" />
                <asp:BoundField DataField="a" HeaderText="剩余条数" 
                    SortExpression="a" />
                <asp:BoundField DataField="faxExpire" HeaderText="传真时间" 
                    SortExpression="faxExpire" DataFormatString="{0:d}" />
                
                <asp:TemplateField HeaderText="客服">
                    <ItemTemplate>
                        <asp:DropDownList ID="ddl" runat="server" DataSourceID="ddlds" 
                            DataTextField="a" DataValueField="id"  >
                        </asp:DropDownList>
                        <asp:SqlDataSource ID="ddlds" runat="server" 
                            ConnectionString="<%$ ConnectionStrings:connectionStrings %>" 
                            SelectCommand="SELECT [id], [csName]+[csAccount] as a FROM [customservice] ORDER BY [id]">
                        </asp:SqlDataSource>
                    </ItemTemplate>
                </asp:TemplateField>
                
            </Columns>
        </asp:GridView>
        
        <asp:SqlDataSource ID="ds" runat="server" 
            ConnectionString="<%$ ConnectionStrings:connectionStrings %>" 
            ProviderName="System.Data.SqlClient" 
            SelectCommand="">
        </asp:SqlDataSource> --------------------编程问答-------------------- 编辑模板中编辑dataBindings只有自定义绑定，如何是好 --------------------编程问答-------------------- protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
  {
  if (e.Row.RowIndex != -1)
  {
 if (e.Row.RowType == DataControlRowType.DataRow)
  {
  DropDownList ddl=e.Row.FindControl("DropDownList1") as DropDownList;
  ddl.SelectedValue="";
  }
  }
}

--------------------编程问答-------------------- for (int i = 0; i < gridviewcd.Rows.Count; i++)
            {
                DropDownList ddl = gridviewcd.Rows[i].FindControl("ddl") as DropDownList;
                ddl.SelectedValue = gridviewcd.Rows[i].Cells[9].Text;
            }

补充：.NET技术 ,  ASP.NET