System.Data.DataRowView，而不是实际值

我有下面的代码。当我运行程序并运行一次参数为223的存储过程时，然后我用参数为315的蚂蚁运行它，之后再次运行参数，我得到了System.Data。DataRowView"，而不是实际值。你能帮我做一下吗?

private void GetServers()
    {
        IDBManager dbManager = new DBManager (DataProvider.SqlServer);
        dbManager.ConnectionString = @"Data Source=server; Initial Catalog=base;  Integrated Security = SSPI;";
        try
        {
            dbManager.Open();
            dbManager.CreateParameters(1);
            dbManager.AddParameters(0,"@report_id", (txtReportID.Text));
            DataSet ds = new DataSet("Servers");
            ds = dbManager.ExecuteDataSet(CommandType.StoredProcedure, "sp_get_servers_from_report_test");              
            if (ds.Tables[0].Rows.Count > 0)
            {
                chkdListBoxServers.DataSource = ds.Tables[0];
                chkdListBoxServers.DisplayMember = "Servers";
                chkdListBoxServers.ValueMember = "server_name";                 
            }
            else
            {
                MessageBox.Show("No servers or incorrect report id");
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
        finally
        {
            dbManager.Dispose();
        }
    }