AutoMapper 对象映射器

https://docs.automapper.org/

基于约定的对象-对象映射器。100% 有机和无麸质。消除将一个对象映射到另一个对象的所有麻烦。

什么是 AutoMapper？

AutoMapper 是一个简单的小库，旨在解决一个看似复杂的问题——摆脱将一个对象映射到另一个对象的代码。这种类型的代码写起来相当枯燥乏味，那么为什么不发明一个工具来为我们做呢？

 映射可以出现在应用程序的许多地方，但主要是在层之间的边界，例如 UI/Domain 层或 Service/Domain 层之间。一层的关注点经常与另一层的关注点发生冲突，因此对象-对象映射导致分离模型，其中每一层的关注点只能影响该层中的类型。

1. NuGet引用 
AutoMapper

AutoMapper.Extensions.Microsoft.DependencyInjection

2. 添加继承 Profile 的映射关系类 MappingProfile

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using AutoMapper; using TestWebApplication.Model;   namespace TestWebApplication.Extensions {     public class MappingProfile:Profile     {         public MappingProfile()         {             CreateMap<Post, PostResource>()                 .ForMember(d=>d.UpdateTime,s=>s.MapFrom(src=>src.LastModified));             CreateMap<PostResource, Post>();             CreateMap<PO, POResource>();             CreateMap<POResource, PO>();         }     } }

3. 注册服务

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1	builder.Services.AddAutoMapper(typeof(MappingProfile));

4. 客户通过注入IMapper 消费

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using AutoMapper; using Microsoft.AspNetCore.Http; using Microsoft.AspNetCore.Mvc; using Microsoft.EntityFrameworkCore; using TestWebApplication.Model;   namespace TestWebApplication.Controllers {     [Route("api/[controller]")]     [ApiController]     public class TestAutoMapperController : ControllerBase     {         private readonly ILogger<TestAutoMapperController> _logger;         private readonly IMapper _mapper;         private readonly ApplicationDbContext _context;         public TestAutoMapperController(ILogger<TestAutoMapperController> logger, IMapper mapper, ApplicationDbContext context)         {             _logger = logger;             _mapper = mapper;             _context = context;         }           [HttpGet(nameof(GetPostResource))]         public async Task<ActionResult<PostResource>> GetPostResource()         {             Post post = new Post             {                 Title = "ASP.NET Core 项目实战",                 Author = "杨中科",                 Body = "基于DDD与前扣端分离",                 LastModified = DateTime.Now,                 Remark = "From:" + nameof(Post)             };             PostResource postResource = _mapper.Map<Post, PostResource>(post);             postResource.Remark += $" To {nameof(PostResource)}";             return Ok(postResource);         }         [HttpGet(nameof(GetPost))]         public async Task<ActionResult<Post>> GetPost()         {             PostResource postResource = new PostResource             {                 Title = "ASP.NET Core 项目实战",                 Author = "杨中科",                 Body = "基于DDD与前扣端分离",                 UpdateTime = DateTime.Now,                 Remark = "From:" + nameof(PostResource)             };             Post post = _mapper.Map<PostResource, Post>(postResource);             post.Remark += $" To {nameof(Post)}";             return Ok(post);         }         [HttpGet(nameof(GetPO))]         public async Task<ActionResult<IEnumerable<POResource>>> GetPO()         {             var poList = await _context.PO.Take(3).ToListAsync();             IEnumerable<POResource> poResources = _mapper.Map<IEnumerable<PO>, IEnumerable<POResource>>(poList);             return Ok(poResources);         }     } }

　　

 在AutoFac中注册：

https://www.cnblogs.com/friend/p/16915214.html