Automapper says Mapper.Map is obsolete, global map

问题:

I had defined in my project a global Automapper configuration that would allow me to use Mapper.Map<targetType>(sourceObject); in my code. (See my configuration below.)

I updated the NuGet package, and I see the message that Mapper.Map is obsolete/depreciated. I went back to Automapper on GitHub and see examples like this:

[Test]
public void Example()
{
    var config = new MapperConfiguration(cfg =>
    {
        cfg.CreateMap<Source1, SubDest1>().FixRootDest();
        cfg.CreateMap<Source2, SubDest2>().FixRootDest();
    });

    config.AssertConfigurationIsValid();

    var mapper = config.CreateMapper();

    var subDest1 = mapper.Map<Source1, SubDest1>(new Source1 {SomeValue = "Value1"});
    var subDest2 = mapper.Map<Source2, SubDest2>(new Source2 {SomeOtherValue = "Value2"});

    subDest1.SomeValue.ShouldEqual("Value1");
    subDest2.SomeOtherValue.ShouldEqual("Value2");
}

Am I going to have to create a configuration in EVERY method that uses a mapping?

My current global configuration:

namespace PublicationSystem.App_Start
{
    public class AutoMapperConfig
    {
        public static void CreateMaps()
        {
            CreateProjectMaps();
        }

        private static void CreateProjectMaps()
        {
            Mapper.CreateMap<Project, ProjectCreate>();
            Mapper.CreateMap<Project, ProjectSelectable>();
            //...
        }
    }
}

UPDATE: Thanks to some coaching from Scott Chamberlain I have created a class like this:

    public class MkpMapperProfile : AutoMapper.Profile
    {
        protected override void Configure() 
        {
            this.CreateMap<Project, ProjectCreate>();

            this.CreateMap<Project, ProjectSelectable>();

            this.CreateMap<Project, ProjectDetails>();

            // Many Many other maps
        }
    }

I'm thinking I should have the 'MapperConfiguration' in my BaseController class. I started to do something like this:

public partial class BaseController : Controller
{

    private MapperConfiguration mapConfig;

    public BaseController()
    {
        db = new MkpContext();
        SetMapperConfig();
    }

    private void SetMapperConfig()
    {
        mapConfig = new MapperConfiguration(cfg =>
            {
                cfg.AddProfile<MkpMapperProfile>();
            });
    }

    public BaseController(MapperConfiguration config)
    {
        db = new MkpContext();
        this.mapConfig = config;
    }
}

Am I on the right track?

回答1:

This is how I've handled it.

Create maps in a Profile, taking care to use the Profile's CreateMap method rather than Mapper's static method of the same name:

internal class MappingProfile : Profile
{
    protected override void Configure()
    {
        CreateMap<Project, ProjectCreate>();
    }
}

Then, wherever dependencies are wired-up (ex: Global.asax or Startup), create a MapperConfiguration and then use it to create an IMapper.

var mapperConfiguration = new MapperConfiguration(cfg =>
    {
        cfg.AddProfile(new MappingProfile());
    });

Then, use the configuration to generate an IMapper:

var mapper = mapperConfiguration.CreateMapper();

Then, register that mapper with the dependency builder (I'm using Autofac here)

builder.RegisterInstance(mapper).As<IMapper>();

Now, wherever you need to map stuff, declare a dependency on IMapper:

internal class ProjectService : IProjectService {
    private readonly IMapper _mapper;
    public ProjectService(IMapper mapper) {
         _mapper = mapper;
    }
    public ProjectCreate Get(string key) {
        var project = GetProjectSomehow(key);
        return _mapper.Map<Project, ProjectCreate>(project);
    }
}

回答2:

I'm using version 5.2.0, support to create maps in constructors instead of override configure.

public class MappingProfile : Profile
{
    public MappingProfile()
    {
        CreateMap<Project, ProjectDto>();
    }
}

In Global.asax.cs call like:

Mapper.Initialize(c=>c.AddProfile<MappingProfile>());

Hope this help.

回答3:

This is new in AutoMapper 4.2. There is a blog post by Jimmy Bogard on this: Removing the static API from AutoMapper. It claims that

The IMapper interface is a lot lighter, and the underlying type is now just concerned with executing maps, removing a lot of the threading problems...

The new syntax: (pasted from the blog post)

var config = new MapperConfiguration(cfg => {
  cfg.CreateMap<User, UserDto>();
});

---

If you just want the "old way" of doing this. The latest version 4.2.1 has brought back some tradition. Just use

CreateMap<Project, ProjectCreate>();

instead of

Mapper.CreateMap<Project, ProjectCreate>();

The old code will work just fine.

回答4:

You can find configured AutoMapper 4.2 in my ASP.NET MVC Template project here: https://github.com/NikolayIT/ASP.NET-MVC-Template

1. Create these classes: https://github.com/NikolayIT/ASP.NET-MVC-Template/tree/master/ASP.NET%20MVC%205/Web/MvcTemplate.Web.Infrastructure/Mapping

2. Annotate view models with IMapFrom<>: https://github.com/NikolayIT/ASP.NET-MVC-Template/blob/master/ASP.NET%20Core/Web/AspNetCoreTemplate.Web/ViewModels/Settings/SettingViewModel.cs

3. Use it as .To<SomeViewModel>(). Example: https://github.com/NikolayIT/ASP.NET-MVC-Template/blob/master/ASP.NET%20MVC%205/Web/MvcTemplate.Web/Controllers/HomeController.cs#L27

回答5:

Mapper.Initialize(cfg => {
    cfg.CreateMap<Source, Dest>();
});