Entity framework 清除链接到实体框架的DataGridView数据源
我是实体框架的新手,我有一个连接到实体框架的Entity framework 清除链接到实体框架的DataGridView数据源,entity-framework,linq,datagridview,linq-to-entities,Entity Framework,Linq,Datagridview,Linq To Entities,我是实体框架的新手,我有一个连接到实体框架的DataGridView,如下所示 dgvDebit.DataSource = (from daily in accountingEntities.DailyAccounts join voucherdetails in accountingEntities.VoucherDetails on daily.DailyId equals voucherdetails.DailyId
DataGridView
,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
datasource,但我所做的每一件事都失败了-请在此提供帮助?好的,所以您想绑定到您拥有的类型的空列表
步骤1: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; }
}
步骤2: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();
步骤3:如果要“清除”DataGridView,但保留列,现在可以使用:
dgvDebit.DataSource = new List<ResultDTO>();
dgvDebit.DataSource=new List();
好的,因此您希望绑定到现有类型的空列表
步骤1: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; }
}
步骤2: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();
步骤3:如果要“清除”DataGridView,但保留列,现在可以使用:
dgvDebit.DataSource = new List<ResultDTO>();
dgvDebit.DataSource=new List();
dgvDebit.DataSource=null代码>应清除数据源-是否有此错误?(如果是这样:您会得到什么错误??)dgvDebit.DataSource=null;它的工作,但它的清晰列太多,所以当我再次加载datagridview时,我松散的网格格式dgvDebit.DataSource=null代码>应清除数据源-是否有此错误?(如果是这样:您会得到什么错误??)dgvDebit.DataSource=null;它的工作,但它的清晰列太多,所以当我再次加载datagridview时,我非常感谢您为我的answer@HusseinAl-不客气-很高兴我能帮上忙!祝你度过愉快的一天谢谢你把时间花在我的工作上answer@HusseinAl-不客气-很高兴我能帮上忙!祝你有美好的一天