C# 使用AutoMapper实现类映射

写在前面

AutoMapper是一个用于.NET中简化类之间的映射的扩展库；可以在执行对象映射的过程，省去的繁琐转换代码，实现了对DTO的快速装配，有效的减少了代码量。

通过NuGet安装，AutoMapper，由于本例用到了DI,所以需要顺便安装一下 AutoMapper.Extensions.Microsoft.DependencyInjection

代码实现

using AutoMapper;
using AutoMapper.Internal;
using Microsoft.Extensions.DependencyInjection; IServiceCollection services = new ServiceCollection();
services.AddTransient<ISomeService>(sp => new FooService(5));
services.AddAutoMapper(typeof(Source));
var provider = services.BuildServiceProvider();
using (var scope = provider.CreateScope())
{var mapper = scope.ServiceProvider.GetRequiredService<IMapper>();foreach (var typeMap in mapper.ConfigurationProvider.Internal().GetAllTypeMaps()){Console.WriteLine($"{typeMap.SourceType.Name} -> {typeMap.DestinationType.Name}");}foreach (var service in services){Console.WriteLine(service.ServiceType + " - " + service.ImplementationType);}var dest = mapper.Map<Dest2>(new Source2());Console.WriteLine(dest!.ResolvedValue);
}Console.ReadKey();public class Source
{public int Id { get; set; }public string Name { get; set; }
}public class Dest
{public int ResolvedValue { get; set; }}public class Source2
{public string Name { get; set; }public int ResolvedValue { get; set; }
}public class Dest2
{public int ResolvedValue { get; set; }
}/// <summary>
/// 映射表1
/// </summary>
public class Profile1 : Profile
{public Profile1(){CreateMap<Source, Dest>();}
}/// <summary>
/// 映射表1
/// </summary>
public class Profile2 : Profile
{public Profile2(){CreateMap<Source2, Dest2>().ForMember(d => d.ResolvedValue, opt => opt.MapFrom<DependencyResolver>());}
}public class DependencyResolver : IValueResolver<object, object, int>
{private readonly ISomeService _service;public DependencyResolver(ISomeService service){_service = service;}public int Resolve(object source, object destination, int destMember, ResolutionContext context){return _service.Modify(destMember);}
}public interface ISomeService
{int Modify(int value);
}public class FooService : ISomeService
{private readonly int _value;public FooService(int value){_value = value;}public int Modify(int value) => value + _value;
}