Automapper: bidirectional mapping with ReverseMap() and ForMember()

Question

I have the case where I want to map an entity to a viewmodel and back. I have to specify the mapping explicitly with ForMember() because their properties do not share the exact same names. Here is a short example of how my classes look like:

public class PartTwo {     public int Integer { get; set; } }  public class PartTwoViewModel {     public int PartInteger { get; set; } } 

And I want to use them this way:

Mapper.CreateMap<PartTwo, PartTwoViewModel>()     .ForMember(dst => dst.PartInteger, opt => opt.MapFrom(src => src.Integer))     .ReverseMap();  var partTwoViewModel = new PartTwoViewModel() { PartInteger = 42 }; var partTwo = Mapper.Map<PartTwoViewModel, PartTwo>(partTwoViewModel); Assert.AreEqual(partTwoViewModel.PartInteger, partTwo.Integer); 

But it does not match the property PartInteger to Integer. (Integer is 0.)

Is there a way to make this work? (When the properties of both classes have the same names it works.) Do I have to set some kind of option in the method ForMember()?

Answer 1

ReverseMap returns an IMappingExpression that represents the reversal of the mapping. Once you call, it subsequent calls will be for configuring the reversal of the map.

Here's an example:

Mapper.CreateMap<CartItemDto, CartItemModel>()       .ForMember(dest => dest.ExtendedCost, opt => opt.Ignore())       .ReverseMap()           .ForMember(dest => dest.Pricing, opt => opt.Ignore()) 

This will ignore the Pricing field in the reverse direction.