Why I get exception when I try to use AutoMapper?

Question

I use AutoMapper in my .NET CORE 2.2 project.

I get this exception:

Missing type map configuration or unsupported mapping. Mapping types: SaveFridgeTypeModel -> FridgeType College.Refrigirator.Application.SaveFridgeTypeModel -> College.Refrigirator.Domain.FridgeType

On This row:

var fridgeType = _mapper.Map<SaveFridgeTypeModel, FridgeType>(model);

Here is defenition of FridgeType class:

public class FridgeType : IEntity , IType
{
    public FridgeType()
    {
        Fridges = new HashSet<Fridge>();
    }
    public int ID { get; set; }
    //Description input should be restricted 
    public string Description { get; set; }
    public string Text { get; set; }
    public ICollection<Fridge> Fridges { get; private set; }
}

Here is defenition of SaveFridgeTypeModel class:

public class SaveFridgeTypeModel
{
    public string Description { get; set; }
    public string Text { get; set; }
}

I add this row:

    services.AddAutoMapper(typeof(Startup));

To ConfigureServices function in Startup class.

UPDATE

I forgot to add mappin configuration to the post.

Here is mapping configs class:

public class ViewModelToEntityProfile : Profile
{
    public ViewModelToEntityProfile()
    {
        CreateMap<SaveFridgeTypeModel, FridgeType>();
    }
}

Any idea why I get the exception above?

you need to configure mappings first, see : https://stackoverflow.com/q/40275195/1875256 — Ehsan Sajjad, Sep 30 '19 at 10:29
As the error says there is no map from `SaveFridgeModelType` to `FridgeType`. — Vidmantas Blazevicius, Sep 30 '19 at 10:29
Is `ViewModelToEntityProfile` in the same asssembly as `Startup`? By writing `AddAutomapper(typeof(Startup))` you basically said only take maps from this assembly — Vidmantas Blazevicius, Sep 30 '19 at 10:36
@Michael you need to check the type of model, if you are using Entity Framework it could be using a proxy — JH_Dev, Sep 30 '19 at 10:37
@VidmantasBlazevicius thanks for answer. ViewModelToEntityProfile in another project.Is it can be a reason?How do I config AddAutomapper() if ViewModelToEntityProfile in another proj? — Michael, Sep 30 '19 at 10:45
I mean path of least resistance i guess would be to do `AddAutomapper(typeof(ViewModelToEntityProfile))` — Vidmantas Blazevicius, Sep 30 '19 at 10:46

score 2 · Accepted Answer · answered Sep 30 '19 at 10:54

You need to use the type from the assembly where your maps are when registering automapper with DI.

AddAutomapper(typeof(ViewModelToEntityProfile));

If you had multiple assemblies with maps - you could use another overload:

AddAutomapper(typeof(ViewModelToEntityProfile), typeof(SomeOtherTypeInOtherAssembly));

score -1 · Answer 2 · answered Sep 30 '19 at 11:03

After creating mapping config class you need to add the AutoMapperConfiguration in the Startup.cs as shown below:

  public void ConfigureServices(IServiceCollection services) {
    // .... Ignore code before this

   // Auto Mapper Configurations
    var mappingConfig = new MapperConfiguration(mc =>
    {
        mc.AddProfile(new ViewModelToEntityProfile());
    });

    IMapper mapper = mappingConfig.CreateMapper();
    services.AddSingleton(mapper);

    services.AddMvc();
}

Why I get exception when I try to use AutoMapper?

2 Answers2