当输入为 IQueryable 时，无法将 Automapper 设为 return 派生类型

Question

我可以将 Automapper 的 .Map 转换为 return 派生类型，但不能在 IQueryable.

中

数据结构：

public class Order { }
public class OnlineOrder : Order { }
public class MailOrder : Order { }

public class OrderDto { }
public class OnlineOrderDto : OrderDto { }
public class MailOrderDto : OrderDto { }

设置（~复制 from documentation）：

var mapperConfiguration = new MapperConfiguration(cfg =>
{
    cfg.CreateMap<Order, OrderDto>()
        .Include<OnlineOrder, OnlineOrderDto>()
        .Include<MailOrder, MailOrderDto>();
    cfg.CreateMap<OnlineOrder, OnlineOrderDto>();
    cfg.CreateMap<MailOrder, MailOrderDto>();
});

var order = new OnlineOrder();
var orders = new List<Order> { order }.AsQueryable();

var mapper = mapperConfiguration.CreateMapper().Map<OrderDto>(order); // is of type OnlineOrderDto, it works!

我尝试过的：

var projectTo = orders.ProjectTo<OrderDto>(mapperConfiguration); // is of type OrderDto, boo!
var useAsDataSource = orders.UseAsDataSource(mapperConfiguration).For<OrderDto>(); // is of type OrderDto, boo!

我看过 documentation, this , the queryable extensions, and some answers involving LINQ。我觉得我错过了一些明显的东西。

Answer 1

我认为这是不可能的。请参阅此已关闭的错误报告： https://github.com/AutoMapper/AutoMapper/issues/701

当输入为 IQueryable 时，无法将 Automapper 设为 return 派生类型

Can't get Automapper to return the derived type when the input is IQueryable

c#

polymorphism

iqueryable

automapper