[求助]在EditItemTemplate创建动态DropDownList问题

 <asp:TemplateColumn HeaderText=" 分类"  ItemStyle-Width="50">
  <ItemTemplate>
  <%# Pictype(DataBinder.Eval(Container.DataItem ,"TypeID").ToString())%>

   </ItemTemplate>
  <EditItemTemplate>
  <asp:DropDownList ID="TypeID" runat="server">
  </asp:DropDownList>
  </EditItemTemplate> 
 </asp:TemplateColumn>

protected void DDownList(){
    string connStr="server=" + ConfigurationSettings.AppSettings["ServerName"] + ";User ID="+ ConfigurationSettings.AppSettings["UserID"] +"; password="+ ConfigurationSettings.AppSettings["UserPassword"] +";Database=" + ConfigurationSettings.AppSettings["dbBase"] + "";
    SqlConnection conn =new SqlConnection(connStr);
    SqlDataAdapter dr = new SqlDataAdapter("Select * from tbl_PicType",conn);
    conn.Open();
    DataSet ds=new DataSet();
    dr.Fill(ds,"DDown");
    TypeID.DataSource=ds;
    TypeID.DataTextField="TypeName";
    TypeID.DataValueField="TypeID";
    TypeID.DataBind();
}

我试了好多次多是错误提示无TypeID，能不能再EditItemTemplate中间动态创建DorpDownList,要是能，怎么创建呢？