protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            Dictionary<string, string> listItems = GetListItemsForDropDownList();

            rg_number_ddl.DataSource = listItems;
            rg_number_ddl.DataValueField = "Key";
            rg_number_ddl.DataTextField = "Value";
            rg_number_ddl.DataBind();

            //выгрузка данных на стриницу
            using (SqlConnection SelectSqlConn = new SqlConnection(RashodConnect))
            {
                try
                {
                    if (SelectSqlConn.State == ConnectionState.Closed) SelectSqlConn.Open();

                    SqlCommand SelectSqlComm = new SqlCommand("select * from rg_group", SelectSqlConn);
                    SelectSqlComm.CommandType = CommandType.Text;

                    gv_rg_group.DataSource = SelectSqlComm.ExecuteReader();
                    gv_rg_group.DataBind();
                }
                catch (Exception ex)
                {
                    infrom.Text = ex.Message;
                }
                finally
                {
                    //if (SelectSqlConn.State == ConnectionState.Open) SelectSqlConn.Close();
                }
            }
        }
    }

    protected void gv_rg_group_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if ((e.Row.RowType == DataControlRowType.DataRow))
        {
            DropDownList rg_number_ddl_grid = (DropDownList)e.Row.FindControl("rg_number_ddl_grid");
            Label lb = (Label)e.Row.FindControl("Label1");

            Dictionary<string, string> listItems = GetListItemsForDropDownList();

            rg_number_ddl_grid.DataSource = listItems;
            rg_number_ddl_grid.DataValueField = "Key";
            rg_number_ddl_grid.DataTextField = "Value";
            rg_number_ddl_grid.DataBind();

            System.Data.Common.DbDataRecord ddr = (System.Data.Common.DbDataRecord)e.Row.DataItem;
            rg_number_ddl_grid.SelectedValue = ddr["rg_number"].ToString();

        }
    }