我想扩展@theutz的答案-即这一行:

// services.AddAutoMapper(typeof(Startup));  // <-- newer automapper version uses this signature.

AutoMapper.Extensions.Microsoft.DependencyInjection版本3.2.0中有一个错误(可能)。(我使用的是。net Core 2.0)

这个问题在这个GitHub问题中解决。如果你继承AutoMapper的Profile类存在于你的Startup类所在的程序集之外，如果你的AutoMapper注入是这样的，它们可能不会被注册:

services.AddAutoMapper();

除非您显式指定要搜索AutoMapper概要文件的程序集。

在你的初创公司中也可以这样做。ConfigureServices:

services.AddAutoMapper(<assembies> or <type_in_assemblies>);

其中"assemblies"和"type_in_assemblies"指向应用程序中指定Profile类的程序集。例句:

services.AddAutoMapper(typeof(ProfileInOtherAssembly), typeof(ProfileInYetAnotherAssembly));

我认为(我强调这个词)由于以下无参数重载的实现(来自GitHub的源代码):

public static IServiceCollection AddAutoMapper(this IServiceCollection services)
{
     return services.AddAutoMapper(null, AppDomain.CurrentDomain.GetAssemblies());
}

我们依赖于CLR已经包含AutoMapper配置文件的JITed程序集，这可能是真的，也可能不是真的，因为它们只在需要时被jit(更多细节在这个StackOverflow问题中)。

services.AddAutoMapper ();对我没用。(我用的是Asp。Net Core 2.0)

配置如下

   var config = new AutoMapper.MapperConfiguration(cfg =>
   {                 
       cfg.CreateMap<ClientCustomer, Models.Customer>();
   });

初始化映射器 IMapper mapper = config.CreateMapper();

并将mapper对象作为单例添加到服务中 services.AddSingleton(映射);

这样我就可以添加DI到控制器

  private IMapper autoMapper = null;

  public VerifyController(IMapper mapper)
  {              
   autoMapper = mapper;  
  }

我在我的动作方法中使用了如下

  ClientCustomer customerObj = autoMapper.Map<ClientCustomer>(customer);

我用这种方式解决了它(类似于上面，但我觉得这是一个更干净的解决方案)。net Core 3.x

创建MappingProfile.cs类并使用Maps填充构造函数(我计划使用一个类来保存所有映射)

    public class MappingProfile : Profile
    {
        public MappingProfile()
        {
            CreateMap<Source, Dest>().ReverseMap();
        }
    }

在Startup.cs中，添加下面的内容以添加到DI(程序集参数用于保存映射配置的类，在我的例子中，它是MappingProfile类)。

//add automapper DI
services.AddAutoMapper(typeof(MappingProfile));

在Controller中，像使用其他DI对象一样使用它

    [Route("api/[controller]")]
    [ApiController]
    public class AnyController : ControllerBase
    {
        private readonly IMapper _mapper;

        public AnyController(IMapper mapper)
        {
            _mapper = mapper;
        }
        
        public IActionResult Get(int id)
        {
            var entity = repository.Get(id);
            var dto = _mapper.Map<Dest>(entity);
            
            return Ok(dto);
        }
    }

在。net 6中，你需要在Program.cs文件中添加以下内容:

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

theutz的回答很好，我只想补充一点:

如果你让你的映射配置文件继承自MapperConfigurationExpression而不是profile，你可以非常简单地添加一个测试来验证你的映射设置，这总是很方便:

[Fact]
public void MappingProfile_VerifyMappings()
{
    var mappingProfile = new MappingProfile();

    var config = new MapperConfiguration(mappingProfile);
    var mapper = new Mapper(config);

    (mapper as IMapper).ConfigurationProvider.AssertConfigurationIsValid();
}

我想明白了!细节如下:

Add the main AutoMapper Package to your solution via NuGet. Add the AutoMapper Dependency Injection Package to your solution via NuGet. Create a new class for a mapping profile. (I made a class in the main solution directory called MappingProfile.cs and add the following code.) I'll use a User and UserDto object as an example. public class MappingProfile : Profile { public MappingProfile() { // Add as many of these lines as you need to map your objects CreateMap<User, UserDto>(); CreateMap<UserDto, User>(); } } Then add the AutoMapperConfiguration in the Startup.cs as shown below: public void ConfigureServices(IServiceCollection services) { // .... Ignore code before this // Auto Mapper Configurations var mapperConfig = new MapperConfiguration(mc => { mc.AddProfile(new MappingProfile()); }); IMapper mapper = mapperConfig.CreateMapper(); services.AddSingleton(mapper); services.AddMvc(); } To invoke the mapped object in code, do something like the following: public class UserController : Controller { // Create a field to store the mapper object private readonly IMapper _mapper; // Assign the object in the constructor for dependency injection public UserController(IMapper mapper) { _mapper = mapper; } public async Task<IActionResult> Edit(string id) { // Instantiate source object // (Get it from the database or whatever your code calls for) var user = await _context.Users .SingleOrDefaultAsync(u => u.Id == id); // Instantiate the mapped data transfer object // using the mapper you stored in the private field. // The type of the source object is the first type argument // and the type of the destination is the second. // Pass the source object you just instantiated above // as the argument to the _mapper.Map<>() method. var model = _mapper.Map<UserDto>(user); // .... Do whatever you want after that! } }