如何在C#中使用Dictionary进行自定义订单

Question

我正在尝试根据列表中的所有项目的状态对它们进行排序。我试着用字典按照下面的方式来做，但它给了我一个错误。你能帮我正确地做吗？

根据其状态，顺序应如下：已激活、已暂停、已过期和已耗尽。

var table = _plapsaContext.Coupons;
var query = _plapsaContext.Coupons.AsQueryable();
query.Select(e => new CouponDto{
Id = e.Id,
StartingDate = e.StartingDate,
EndingDate = e.EndingDate,
Amount = e.Amount,
TotalCoupons = e.TotalCoupons,
MinimumAmount = e.MinimumAmount,
RestCoupons = e.RestCoupons,
ContractId = e.ContractId,
Status = (e.EndingDate.Date < DateTime.Now.Date && e.Status != CouponStatus.Paused && e.Status != CouponStatus.Drained) ? CouponStatus.Expired : e.Status,
ContractCode = e.ContractId.HasValue ? e.Contract.Code.ToString() : null,
OwnerAssociationCode = e.OwnerAssociactionCode,
BuildingManagerName = e.ContractId.HasValue ? e.Contract.BuildingManagerName : null,
ExcludeFunctionalUnits = e.ExcludeFunctionalUnits
});
Dictionary<CouponStatus, int> orderCoupons = new Dictionary<CouponStatus, int>
{
{ CouponStatus.Activated, 0 },
{ CouponStatus.Paused, 1 },
{ CouponStatus.Expired, 2 },
{ CouponStatus.Drained, 3 },
};
Array.Sort(query.ToArray(), (p, q) => orderCoupons[p.Status].CompareTo(orderCoupons[q.Status]));
Console.WriteLine(query);
return (IQueryable<CouponDto>)query;

我希望你能帮助我！非常感谢！

Answer 1

这个查询应该按照所需的方式进行排序。我认为你不需要在这里对字典进行排序。以下查询将对服务器端的数据进行排序。

var query = _plapsaContext.Coupons.AsQueryable();
var dtoQuery = query
.Select(e => new CouponDto
{
Id = e.Id,
StartingDate = e.StartingDate,
EndingDate = e.EndingDate,
Amount = e.Amount,
TotalCoupons = e.TotalCoupons,
MinimumAmount = e.MinimumAmount,
RestCoupons = e.RestCoupons,
ContractId = e.ContractId,
Status = (e.EndingDate.Date < DateTime.Now.Date && e.Status != CouponStatus.Paused && e.Status != CouponStatus.Drained) ? CouponStatus.Expired : e.Status,
ContractCode = e.ContractId.HasValue ? e.Contract.Code.ToString() : null,
OwnerAssociationCode = e.OwnerAssociactionCode,
BuildingManagerName = e.ContractId.HasValue ? e.Contract.BuildingManagerName : null,
ExcludeFunctionalUnits = e.ExcludeFunctionalUnits
});
dtoQuery = dtoQuery
.OrderBy(e => e.Status == CouponStatus.Activated ? 0 
: e.Status == CouponStatus.Paused ? 1
: e.Status == CouponStatus.Expired ? 2
: e.Status == CouponStatus.Drained : 3
);
return dtoQuery;