Question

我是Entity Framework的新手，我有一个DataGridView连接到Entity Framework，如下所示

dgvDebit.DataSource = (from daily in accountingEntities.DailyAccounts
                       join voucherdetails in accountingEntities.VoucherDetails on daily.DailyId equals voucherdetails.DailyId
                       where voucherdetails.VoucherId == keyvalue
                       group voucherdetails by daily.DailyName into dgroup
                       select new
                              {
                                  DailyName = dgroup.Key,
                                  SumOfDebit = dgroup.Sum(s => s.Debit)
                              }).ToList();

我的问题是：我想清除DataGridView数据源，但我所做的每件事都失败了 - 请在这里有任何帮助吗？

Answer 1

好的，所以你想要绑定到你拥有的类型的空列表。

第1步：为查询结果返回类型定义.NET类型：

public class ResultDTO
{
    public string DailyName { get; set; }
    public decimal SumOfDebit { get; set; }
}

第2步：将“正常”查询更改为：

dgvDebit.DataSource = (from daily in accountingEntities.DailyAccounts
                       join voucherdetails in accountingEntities.VoucherDetails on daily.DailyId equals voucherdetails.DailyId
                       where voucherdetails.VoucherId == keyvalue
                       group voucherdetails by daily.DailyName into dgroup
                       select new ResultDTO
                              {
                                  DailyName = dgroup.Key,
                                  SumOfDebit = dgroup.Sum(s => s.Debit)
                              }).ToList();

第3步：如果您要“清除”DataGridView，但保留列，您现在可以使用：

dgvDebit.DataSource = new List<ResultDTO>();

清除链接到Entity Framework的DataGridView数据源

1 个答案: