Trying to add AutoMapper to Asp.net Core 2?

问题

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?

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You likely updated your ASP.NET Core dependencies, but still using outdated AutoMapper.Extensions.Microsoft.DependencyInjection package.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

回答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));

回答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);

回答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

回答5:

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 ));

回答6:

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) /*, ...*/);

回答7:

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

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

来源：https://stackoverflow.com/questions/50411188/trying-to-add-automapper-to-asp-net-core-2