Question

您好我正在使用自动映射器来映射条件实体，该条件实体在不使用After map的情况下无法工作，但在After Map中工作正常，我不会使用它。我想从Domain.PermanentPlacement映射InvoiceLineCreditHeader，但有条件。

以下是映射代码。

 MauritiusMapper.CreateMap<Domain.PermanentPlacement, InvoiceLineCreditHeader>()
                                .ForMember(desc => desc.ApplicantName, o => o.MapFrom(source => source.Candidate.FullName))
                                .ForMember(desc => desc.DatePlaced, o => o.MapFrom(source => source.PlacementDate))
                                .ForMember(desc => desc.ApproveDate, o => o.MapFrom(source => source.LastAuditItem.DateOfAction))
                                .ForMember(desc => desc.CheckedBy, o => o.MapFrom(source => source.StartCheckedBy))
                                .ForMember(desc => desc.Job, o => o.MapFrom(source => source.JobTitle));

        MauritiusMapper.CreateMap<InvoiceLineCreditSearchResult, InvoiceLineCreditData>()
            .ForMember(d => d.InvoiceLineCredits, o => o.MapFrom(s => s.Credits))
            .ForMember(d => d.InvoiceLineCreditHeader, o => o.MapFrom(s => s.InvoiceLine))
            .ForMember(d => d.CreditReasons, o => o.MapFrom(s => s.CreditReasons))
            .ForMember(d => d.CreditStatuses, o => o.MapFrom(s => s.CreditStatuses))
            .ForMember(d => d.InvoiceLineCreditHeader, o => o.MapFrom(s => s.InvoiceLine.TransactionLines.OfType<PermanentPlacementTransactionLine>().FirstOrDefault()?.PermanentPlacement ?? s.ReissuePermanentPlacement))

这给出了错误

表达式树lambda可能不包含空传播运算符。

Why can't I use the null propagation operator in lambda expressions?

解释了这一点

如果我使用Aftermap，它可以正常工作。

        MauritiusMapper.CreateMap<InvoiceLineCreditSearchResult, InvoiceLineCreditData>()
            .ForMember(d => d.InvoiceLineCredits, o => o.MapFrom(s => s.Credits))
            .ForMember(d => d.InvoiceLineCreditHeader, o => o.MapFrom(s => s.InvoiceLine))
            .ForMember(d => d.CreditReasons, o => o.MapFrom(s => s.CreditReasons))
            .ForMember(d => d.CreditStatuses, o => o.MapFrom(s => s.CreditStatuses))
            //.ForMember(d => d.InvoiceLineCreditHeader, o => o.MapFrom(s => s.InvoiceLine.TransactionLines.OfType<PermanentPlacementTransactionLine>().FirstOrDefault()?.PermanentPlacement ?? s.ReissuePermanentPlacement))
            .AfterMap((s, d) =>
            {
                var placement
                = s.InvoiceLine.TransactionLines.OfType<PermanentPlacementTransactionLine>().FirstOrDefault()?.PermanentPlacement ?? s.ReissuePermanentPlacement;
                //  if (placement == null) return;


                d.InvoiceLineCreditHeader.ApplicantId = placement.ApplicantId;
                d.InvoiceLineCreditHeader.ApplicantName = placement.Candidate.FullName;
                d.InvoiceLineCreditHeader.Job = placement.JobTitle;
                d.InvoiceLineCreditHeader.DatePlaced = placement.PlacementDate;
                d.InvoiceLineCreditHeader.PlacedBy = placement.PlacedBy;
                d.InvoiceLineCreditHeader.ApprovedBy = placement.ApprovedBy;
                d.InvoiceLineCreditHeader.ApproveDate = placement.LastAuditItem.DateOfAction;
                d.InvoiceLineCreditHeader.CheckedBy = placement.StartCheckedBy;
                d.InvoiceLineCreditHeader.StartDate = placement.StartDate;
            });

自动映射器中有什么办法可以在不使用AfterMap的情况下实现这一点吗？也有条件，但它也使用linq表达。

有什么想法吗？

Answer 1

您需要在

中找到?.运算符的替代方法

s.InvoiceLine.TransactionLines.OfType<PermanentPlacementTransactionLine>()
    .FirstOrDefault()?.PermanentPlacement

Select PermanentPlacement之前FirstOrDefault非常简单：

s.InvoiceLine.TransactionLines.OfType<PermanentPlacementTransactionLine>()
    .Select(e => e.PermanentPlacement).FirstOrDefault()

Answer 2

您可以使用所需的逻辑创建单独的方法：

private InvoiceLineCreditHeader GetInvoiceLineCreditHeader(InvoiceLineCreditSearchResult result)
{
    // todo: get InvoiceLineCreditHeader conditionally
    InvoiceLineCreditHeader header = new InvoiceLineCreditHeader();
    return header;
}

并将其称为：

.ForMember(d => d.InvoiceLineCreditHeader, o => o.MapFrom(s => GetInvoiceLineCreditHeader(s)))

自动映射器映射条件实体，它不使用After map而无法工作

2 个答案: