Trying to add AutoMapper to Asp.net Core 2?

Question

I worked on a asp.net core 1.1 project a while ago and use in projetc AutoMapper.

in asp.net core 1.1, I add services.AddAutoMapper() in startup file :

StartUp file in asp.net core 1.1:

    public void ConfigureServices(IServiceCollection services)
    {
        //Some Code

        services.AddMvc();
        services.AddAutoMapper();
    }

And I use AutoMapper in Controller easily.

Controller :

 public async Task<IActionResult> AddEditBook(AddEditBookViewModel model)
 {
    Book bookmodel = AutoMapper.Mapper.Map<AddEditBookViewModel, Book>(model);
    context.books.Add(bookmodel);
    context.SaveChanges();
 }

And everything was fine. But I'm currently working on a Asp.net Core 2 project and I get the error with services.AddAutoMapper() in sturtap file.

Error CS0121 The call is ambiguous between the following methods or properties: 'ServiceCollectionExtensions.AddAutoMapper(IServiceCollection, params Assembly[])' and 'ServiceCollectionExtensions.AddAutoMapper(IServiceCollection, params Type[])'

What is the reason for this error? Also, services.AddAutoMapper in asp.net core 2 has some parameters. what should I send to this parameter?

Grof

Don't mix Versions of .NET Core. You probably have references to some 1.1 assemblies of .NET Core or ASP.NET Core. YOu have to update ALL of them to the same version (i.e. 2.0 or 2.1-rc) or you are still referencing an outdated Automapper version – Celebration

Answer 1

You likely updated your ASP.NET Core dependencies, but still using outdated AutoMapper.Extensions.Microsoft.DependencyInjection package.

For ASP.NET Core you need at least Version 3.0.1 from https://www.nuget.org/packages/AutoMapper.Extensions.Microsoft.DependencyInjection/3.0.1

Which references AutoMapper 6.1.1 or higher.

AutoMapper (>= 6.1.1)

Microsoft.Extensions.DependencyInjection.Abstractions (>= 2.0.0)

Microsoft.Extensions.DependencyModel (>= 2.0.0)

The older packages depend on Microsoft.Extensions.DependencyInjection.Abstractions 1.1.0 and can't be used with ASP.NET Core since there have been breaking changes between Microsoft.Extensions.DependencyInjection.Abstractions 1.1.0 and 2.0

Celebration

Thanks. i updated AutoMapper.Extensions.Microsoft.DependencyInjection and error solved. – Grof

do in console dotnet add package AutoMapper.Extensions.Microsoft.DependencyInjection --version 8.0.1 – Hasan

For dotnet 5.0, AutoMapper.Extensions.Microsoft.DependencyInjection 8.1.1 doesn't seem to work. – Boggess

Answer 2

If you are using AspNet Core 2.2 and AutoMapper.Extensions.Microsoft.DependencyInjection v6.1 You need to use in Startup file

services.AddAutoMapper(typeof(Startup));

Para

FYI for the next one that bumps into this: I had to install Microsoft.Extensions.DependencyInjection.Abstractions to make services.AddAutoMapper(typeof(Startup)); work – Shorthand

on .net core 2.2,this eliminated the build error for me, but still failed at runtime for lack of mapping configurations.. what worked for me was to list all of my profile classes inside the statement. i.e: services.AddAutoMapper(typeof(profileClassName1),typeof(profileClassName2)); – Wang

@nirweiner's comment is correct, but you only have to point to one of the profile classes, because it is asking for an assembly to search in. dev-siberia's answer works if your profile configurations are in the same assembly. – Danita

Answer 3

In new version (6.1) of AutoMapper.Extensions.Microsoft.DependencyInjection nuget package you should use it as follows:

services.AddAutoMapper(Type assemblyTypeToSearch);
// OR
services.AddAutoMapper(params Type[] assemblyTypesToSearch);

e.g:

services.AddAutoMapper(typeOf(yourClass)); 

Butterwort

What do you mean by assemblyType? I have tons of profile which is why i can't afford adding them one by one. Sorry new in C# here. Thanks! – Rotten

Something like services.AddAutoMapper(typeOf(yourClass)); – Butterwort

Yeah, i mean those answers are mentioned above and it truly works but i was just wondering what could be the explanation of what assemblyType. Sorry i'm really a noob one – Rotten

I mean one or multi types in an assembly. if you wanna find, what is an assembly #1362742 – Butterwort

Answer 4

None of these worked for me, I have a .NET Core 2.2 project and the complete code for configuring the mapper looks like this(part of ConfigureService() method):

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

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

Then I have my Mappings class which I've placed in the BL project:

public class SimpleMappings : Profile
    {
        public SimpleMappings()
        {
            CreateMap<DwUser, DwUserDto>();
            CreateMap<DwOrganization, DwOrganizationDto>();
        }
    }

And finally the usage of the mapper looks like this:

public class DwUserService : IDwUserService
    {
        private readonly IDwUserRepository _dwUserRepository;
        private readonly IMapper _mapper;

        public DwUserService(IDwUserRepository dwUserRepository, IMapper mapper)
        {
            _dwUserRepository = dwUserRepository;
            _mapper = mapper;
        }

        public async Task<DwUserDto> GetByUsernameAndOrgAsync(string username, string org)
        {
            var dwUser = await _dwUserRepository.GetByUsernameAndOrgAsync(username, org).ConfigureAwait(false);
            var dwUserDto = _mapper.Map<DwUserDto>(dwUser);

            return dwUserDto;
        }
}

Here is a similar link on the same topic: How to setup Automapper in ASP.NET Core

Dropout

Thanks so much for posting this complete example! – Power

This is the only example that worked for me. Thanks! – Bunyan

Answer 5

Install package:

Install-Package AutoMapper.Extensions.Microsoft.DependencyInjection -Version 7.0.0

Nuget:
https://www.nuget.org/packages/AutoMapper.Extensions.Microsoft.DependencyInjection/

In Startup Class:

services.AddAutoMapper(typeof(Startup));

Footer

Answer 6

If you are using AspNet Core 2.2.Try changing your code

from:

services.AddAutoMapper();

to:

services.AddAutoMapper(typeof(Startup));

It worked for me.

Adelaideadelaja

Answer 7

In .Net 6, you can do it like

builder.Services.AddAutoMapper(typeof(Program).Assembly); // Since there is no Startup file

OR

builder.Services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());

Basically, it requires the assembly name as shown in screenshot below

Cubature

Answer 8

I solved this by creating a class that inherits AutoMapper.Profile

    public class model_to_resource_profile : Profile
    {
        public model_to_resource_profile()
        {
            CreateMap<your_model_class, your_model_resource_class>();
        }
    }

And adding this line in the Startup.cs:

services.AddAutoMapper(typeof(model_to_resource_profile ));

Sourdough

Answer 9

try this, works with 2.1 and up, i have not used any previous version so can't tell.

services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());

Factitious

This answer is works for me when doing AutoMapper for additional project on my solution. Thank bro. – Rolland

Answer 10

If you are having issue with adding your auto mapper, It is better you check through the type and version you added. If it is not "AutoMapper.Extensions.Microsoft.DependencyInjection", then you won't be able to use "services.AddAutoMapper()". Sometimes, you might mistakenly add "AutoMapper

Waldheim

Answer 11

The official docs: https://automapper.readthedocs.io/en/latest/Dependency-injection.html#asp-net-core

You define the configuration using profiles. And then you let AutoMapper know in what assemblies are those profiles defined by calling the IServiceCollection extension method AddAutoMapper at startup:

services.AddAutoMapper(profileAssembly1, profileAssembly2 /*, ...*/);

or marker types:

services.AddAutoMapper(typeof(ProfileTypeFromAssembly1), typeof(ProfileTypeFromAssembly2) /*, ...*/);

Interlocutor

Answer 12

I also face same issue with .NET 8

It resolved by updating AutoMapper and AutoMapper.Extensions.Microsoft.DependencyInjection to same version

// Add services to the container.
builder.Services.AddAutoMapper(typeof(MappingConfig));

Linstock

I had the same issue, this resolved it for me. I'm also using AutoMapper.Collection.EntityFrameworkCore on version 10.0.0 and had to bring it back to 9.0.0. Have to wait for AutoMapper.Extensions.Microsoft.DependencyInjection to hit version 13.0.1 – Greasy

Answer 13

Dec 6th 2019 Based upon initial attempt in a pluralsight course Building an API with ASP.NET Core by Shawn Wildermuth. As I got the error "...ambiguous 'ServiceCollectionExtensions.AddAutoMapper(IServiceCollection, params Assembly[])..."

I started researching proper syntax to implement AddAutoMapper in Core 2.2. My NuGet reference is version 7.0.0 After the tutorial had me create the Profile class in my Data repository directory which additionally referenced my model nir weiner & dev-siberia's answers above led me to trying to reference the profile class in the Startup.ConfigureServices() by name:

services.AddAutoMapper(typeof(CampProfile));

the content of the profile class is just a (no pun intended) old school map of the data class and the model in its constructor

this.CreateMap<Camp, CampModel>();  

This addressed the poor lack of documentation for this current version.

Respectfully,

ChristianProgrammer

Spoony