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);
        }
    }

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! } }

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();
}

对于使用。net 7的AutoMapper 11.0.1，我开始得到这个异常:

System.ArgumentException: 'GenericArguments[0], 'System.DateTime', on 'T MaxInteger[T](System.Collections.Generic.IEnumerable`1[T])' violates the constraint of type 'T'.'

Inner Exception
VerificationException: Method System.Linq.Enumerable.MaxInteger: type argument 'System.DateTime' violates the constraint of type parameter 'T'.

看这个问题:

系统。DateTime on 'T MaxInteger[T](System.Collections.Generic.IEnumerable ' 1[T])'违反了。net 7使用AutoMapper 11.0.1的T类型约束

这意味着我不能再使用services.AddAutoMapper(typeof(MappingProfile).Assembly);无一例外。

对于AutoMapper.Extensions.Microsoft.DependencyInjection我这样解决它:

services.AddAutoMapper(cfg => cfg.Internal().MethodMappingEnabled = false, typeof(MappingProfile).Assembly);

对于Blazor WebAssembly客户端，解决方案是这样的:

var mapperConfig = new MapperConfiguration(mc =>
{
    //Needed for https://github.com/AutoMapper/AutoMapper/issues/3988
    mc.Internal().MethodMappingEnabled = false;
    mc.AddProfile(new MappingProfile());
});
//mapperConfig.AssertConfigurationIsValid();

IMapper mapper = mapperConfig.CreateMapper();
builder.Services.AddSingleton(mapper);

让我们来看看如何将Auto mapper添加到。net Core应用程序中。

步骤:1 第一步是安装相应的NuGet包:

Install-Package AutoMapper.Extensions.Microsoft.DependencyInjection

一步:2

安装所需的包后，下一步是配置服务。让我们在Startup.cs类中执行:

public void ConfigureServices(IServiceCollection services)
{
    services.AddAutoMapper(typeof(Startup));
    services.AddControllersWithViews();
}

一步:3

让我们开始使用，我们有一个名为User的域对象:

public class User
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public string Address { get; set; }
}

在UI层，我们将有一个视图模型来显示用户信息:

public class UserViewModel
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
}

一步:4

组织映射配置的一个好方法是使用Profiles。我们需要创建从Profile类继承的类，并将配置放在构造函数中:

public UserProfile()
{
    CreateMap<User, UserViewModel>();
}

一步:5

现在，让我们定义一个Controller并使用我们刚刚添加的Auto-Mapping功能:

public class UserController : Controller
{
    private readonly IMapper _mapper;
    public UserController(IMapper mapper)
    {
        _mapper = mapper;
    }
    public IActionResult Index()
    {
        // Populate the user details from DB
        var user = GetUserDetails();
        UserViewModel userViewModel = _mapper.Map<UserViewModel>(user);
        return View(userViewModel);
    }
}

首先，我们将映射器对象注入到控制器中。然后，我们调用Map()方法，它将User对象映射到UserViewModel对象。此外，请注意我们用于本地数据存储的本地方法GetUserDetails。 您可以在我们的源代码中找到它的实现。

我使用的是AutoMapper 6.1.1和asp.net Core 1.1.2。

首先，定义由Automapper的Profile Class继承的Profile类。我创建了IProfile接口，该接口为空，目的只是为了查找该类型的类。

 public class UserProfile : Profile, IProfile
    {
        public UserProfile()
        {
            CreateMap<User, UserModel>();
            CreateMap<UserModel, User>();
        }
    }

现在创建一个单独的类，例如Mappings

 public class Mappings
    {
     public static void RegisterMappings()
     {            
       var all =
       Assembly
          .GetEntryAssembly()
          .GetReferencedAssemblies()
          .Select(Assembly.Load)
          .SelectMany(x => x.DefinedTypes)
          .Where(type => typeof(IProfile).GetTypeInfo().IsAssignableFrom(type.AsType()));

            foreach (var ti in all)
            {
                var t = ti.AsType();
                if (t.Equals(typeof(IProfile)))
                {
                    Mapper.Initialize(cfg =>
                    {
                        cfg.AddProfiles(t); // Initialise each Profile classe
                    });
                }
            }         
        }

    }

现在在MVC核心web项目的Startup.cs文件中，在构造函数中，调用Mapping类，它将在应用程序时初始化所有映射 装载。

Mappings.RegisterMappings();