c# - 如何在 ASP.NET Core 中设置 Automapper

Question

我是 .NET 的新手，因此我决定着手解决 .NET Core 而不是学习“旧方法”。我找到了一篇关于 setting up AutoMapper for .NET Core here 的详细文章，但是对于新手有更简单的演练吗？

Answer 1

我想通了!详情如下:

1. 通过 NuGet 将主要的 AutoMapper 包添加到您的解决方案中.

2. 通过 NuGet 将 AutoMapper 依赖注入(inject)包添加到您的解决方案中.

3. 为映射配置文件创建一个新类。 (我在名为 MappingProfile.cs 的主解决方案目录中创建了一个类，并添加了以下代码。)我将使用 User 和 UserDto对象为例。

    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>();
        }
    }
   

4. 然后在Startup.cs中添加AutoMapperConfiguration，如下所示:

    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();
   
    }
   

5. 要在代码中调用映射对象，请执行如下操作:

    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!
        }
    }