ASP.NET Core使用AutoMapper组件

public static class AutoMapperExtension
{
    /// <summary>
    /// 新增自动映射服务
    /// </summary>
    /// <param name="service"></param>
    /// <returns></returns>
    public static IServiceCollection AddAutoMapper(this IServiceCollection services)
    {
        #region 方案一
        //注册AutoMapper配置扩展类服务
        services.TryAddSingleton<MapperConfigurationExpression>();
        //注册AutoMapper配置扩展类到AutoMapper配置服务去
        services.TryAddSingleton(serviceProvider =>
        {
            var mapperConfigurationExpression = serviceProvider.GetRequiredService<MapperConfigurationExpression>();
            var mapperConfiguration = new MapperConfiguration(mapperConfigurationExpression);
            mapperConfiguration.AssertConfigurationIsValid();
            return mapperConfiguration;
        });
        //注入IMapper接口DI服务
        services.TryAddSingleton(serviceProvider =>
        {
            var mapperConfiguration = serviceProvider.GetRequiredService<MapperConfiguration>();
            return mapperConfiguration.CreateMapper();
        });
        return services;
        #endregion
    }

    /// <summary>
    /// 使用自动映射配置扩展类
    /// </summary>
    /// <param name="applicationBuilder"></param>
    /// <returns></returns>
    public static IMapperConfigurationExpression UseAutoMapper(this IApplicationBuilder applicationBuilder)
    {
        //获取已注册服务AutoMapper配置扩展类
        return applicationBuilder.ApplicationServices.GetRequiredService<MapperConfigurationExpression>();
    }
}
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
    ......
    //添加自动映射组件DI服务
    services.AddAutoMapper();
}
// This method gets called by the runtime. Use this method to configure the Http request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    ......
    //注册组件之后，创建映射对象
　　var expression = app.UseAutoMapper();
    expression.CreateMap<Customer, CustomerDto>();
    expression.CreateMap<Address, AddressDto>();
}

public class BlogsController : Controller
{
    private IMapper _iMapper { get; }
    public BlogsController(IMapper iMapper)
    {
        _iMapper = iMapper;
    }
    // GET: Blogs
    public async Task<IActionResult> Index()
    {
    //对象-对象数据传输
        var dto = _iMapper.Map<CustomerDto>(CustomerInitialize());
        ......
    }
    //手动赋值客户对象数据
    private Customer CustomerInitialize()
    {
        var _customer = new Customer()
        {
            Id = 1,
            Name = "Eduardo Najera",
            Credit = 234.7m,
            Address = new Address() { City = "istanbul", Country = "turkey", Id = 1, Street = "istiklal cad." },
            HomeAddress = new Address() { City = "istanbul", Country = "turkey", Id = 2, Street = "istiklal cad." },
            WorkAddresses = new List<Address>()
            {
                new Address() {City = "istanbul", Country = "turkey", Id = 5, Street = "istiklal cad."},
                new Address() {City = "izmir", Country = "turkey", Id = 6, Street = "konak"}
            },
            Addresses = new List<Address>()
            {
                new Address() {City = "istanbul", Country = "turkey", Id = 3, Street = "istiklal cad."},
                new Address() {City = "izmir", Country = "turkey", Id = 4, Street = "konak"}
            }.ToArray()
        };
        return _customer;
    }
}

var expression = app.UseAutoMapper();
expression.CreateMap<A, ADto>();
expression.CreateMap<B, BDto>();
expression.CreateMap<C, CDto>();
expression.CreateMap<D, DDto>();
......

public sealed class AutoInjectAttribute : Attribute
{
    public Type SourceType { get; }
    public Type TargetType { get; }
    public AutoInjectAttribute(Type sourceType, Type targetType)
    {
        SourceType = sourceType;
        TargetType = targetType;
    }
}

//声明源对象，目标对象
[AutoInject(sourceType: typeof(Customer),targetType:typeof(CustomerDto))]
public class CustomerDto
{
    public int Id { get; set; }
    public string Name { get; set; }
    public Address Address { get; set; }
    public AddressDto HomeAddress { get; set; }
    public AddressDto[] Addresses { get; set; }
    public List<AddressDto> WorkAddresses { get; set; }
    public string AddressCity { get; set; }
}

public class AutoInjectFactory
{
    public List<(Type, Type)> AddAssemblys
    {
        get
        {
            var assemblys =new List<Assembly>() { Assembly.GetExecutingAssembly() };
            List<(Type, Type)> ConvertList = new List<(Type, Type)>();
            foreach (var assembly in assemblys)
            {
                var atributes = assembly.GetTypes()
                    .Where(_type => _type.GetCustomAttribute<AutoInjectAttribute>() != null)
                    .Select(_type => _type.GetCustomAttribute<AutoInjectAttribute>());
                foreach (var atribute in atributes)
                {
                    ConvertList.Add((atribute.SourceType, atribute.TargetType));
                }
            }
            return ConvertList;
        }
    }
}

#region 方案二
//注入AutoMapper配置扩展类服务
services.TryAddSingleton<MapperConfigurationExpression>();
//注入自动注入工厂类服务
services.TryAddSingleton<AutoInjectFactory>();
//注入AutoMapper配置扩展类到AutoMapper配置服务去
services.TryAddSingleton(serviceProvider =>
{
    var mapperConfigurationExpression = serviceProvider.GetRequiredService<MapperConfigurationExpression>();
    //通过自动注入工厂类获取声明数据源对象与DTO对象自动创建映射关系
    var factory = serviceProvider.GetRequiredService<AutoInjectFactory>();
    foreach (var (sourceType, targetType) in factory.AddAssemblys)
    {
        mapperConfigurationExpression.CreateMap(sourceType, targetType);
    }
    var mapperConfiguration = new MapperConfiguration(mapperConfigurationExpression);
    mapperConfiguration.AssertConfigurationIsValid();
    return mapperConfiguration;
});
//注入IMapper接口DI服务
services.TryAddSingleton(serviceProvider =>
{
    var mapperConfiguration = serviceProvider.GetRequiredService<MapperConfiguration>();
    return mapperConfiguration.CreateMapper();
});
return services;
#endregion

/// <summary>
/// 使用自动注入工厂类
/// </summary>
/// <param name="applicationBuilder"></param>
public static void UseAutoInject(this IApplicationBuilder applicationBuilder)
{
   applicationBuilder.ApplicationServices.GetRequiredService<AutoInjectFactory>();
}

app.UseAutoInject();