GridView和DropDownList的嵌套使用

 <EditItemTemplate>
      <asp:DropDownList ID="ddl_EType" runat="server" Width="90%" DataSource='<%# ETypeBind()%>' DataValueField="nBEStyle_ID" DataTextField="cBEStyle_Name" SelectedValue='<%# Bind("nBEProPost_TypeID") %>'>
      </asp:DropDownList>
 </EditItemTemplate>

 public DataTable ETypeBind()
    {
        string sql = "select nBEStyle_ID,cBEStyle_Name from TBase_EType";
        TSqlDB td = new TSqlDB(sql);
        DataTable dt = td.DataSource;

        DataRow dr = dt.NewRow();
        dr["nBEStyle_ID"] = "0";
        dr["cBEStyle_Name"] = "-请选择-";
        dt.Rows.InsertAt(dr, 0);

        return dt;
    }

 protected void Imbt_Add_Click(object sender, ImageClickEventArgs e)
    {
        //增加
        GridViewBind(AddEditRow(GetData()), 0, 0);
    }

protected DataTable AddEditRow(DataTable dt)
    {
        DataRow dr = dt.NewRow();
        dr["nBEProPost_TypeID"] = "0";
        dr["cBEProPost_Name"] = "";
        dr["cBEProPost_Memory"] = "";
        dr["cBEProPost_Remark"] = "";
        dr["State"] = "Insert";
        dt.Rows.InsertAt(dr, 0);
        return dt;
    }