使用参数构造函数和Ninject配置Automapper Profile类

Question

我正在使用 Automapper (v5.1.1.0) 和 Ninject (v3.2.0.0)。我的 Profile 类如下：

public class ApplicationUserResponseProfile : Profile
{
    public ApplicationUserResponseProfile(HttpRequestMessage httpRequestMessage) 
    {
        UrlHelper urlHelper = new UrlHelper(httpRequestMessage);
        CreateMap<ApplicationUser, ApplicationUserResponseModel>()
            .ForMember(dest => dest.Url, opt => opt.MapFrom(src => urlHelper.Link("GetUserById", new { id = src.Id })));
    }

    public ApplicationUserResponseModel Create(ApplicationUser applicationUser)
    {
        return Mapper.Map<ApplicationUserResponseModel>(applicationUser);
    }
}

AutoMapperWebConfiguration是什么：

Mapper.Initialize(cfg =>
        {
            cfg.AddProfile<ApplicationUserResponseProfile>(); // unable to configure
        });

我也尝试将其绑定到Ninject内核中：

var config = new MapperConfiguration(
            c =>
            {
                c.AddProfile(typeof(ApplicationUserResponseProfile));
            });
var mapper = config.CreateMapper();
kernel.Bind<IMapper>().ToConstant(mapper);

还有另一种方法：

Mapper.Initialize(cfg =>
        {
            cfg.ConstructServicesUsing((type) => kernel.Get(type));
            cfg.AddProfile(typeof(ApplicationUserResponseProfile));
        });

但是无论哪种方式都会出现错误 -

没有为此对象定义无参数构造函数

请帮帮我。我无法使用Ninject配置带有参数的AutoMapper配置类。是否有其他解决此问题的方法？

- Asraf Uddin Ahmed

Answer 1

我用了不同的方法解决了这个问题。我将 automapper 从静态方式迁移到了 Profile 方式。

public class ApplicationUserResponseFactory
{
    private MapperConfiguration _mapperConfiguration;
    public ApplicationUserResponseFactory(HttpRequestMessage httpRequestMessage) 
    {
        UrlHelper urlHelper = new UrlHelper(httpRequestMessage);
        _mapperConfiguration = new MapperConfiguration(cfg =>
        {
            cfg.CreateMap<ApplicationUser, ApplicationUserResponseModel>()
                .ForMember(dest => dest.Url, opt => opt.MapFrom(src => UrlHelper.Link("GetUserById", new { id = src.Id })));
        });

    }

    public ApplicationUserResponseModel Create(ApplicationUser applicationUser)
    {
        return _mapperConfiguration.CreateMapper().Map<ApplicationUserResponseModel>(applicationUser);
    }
}

我已经找到了迁移过程这里。

- Asraf Uddin Ahmed

Answer 2

您可以像这样创建一个解析器：

public class YourResolver : IValueResolver<ApplicationUser, ApplicationUserResponseModel, string>
{
    HttpRequestMessage HttpRequestMessage { get; }
  
    public YourResolver(HttpRequestMessage httpRequestMessage)
    {
      HttpRequestMessage = httpRequestMessage;
    }
  
    public string Resolve(ApplicationUser source, ApplicationUserResponseModel destination, string destMember, ResolutionContext context)
    {
       //do something with your HttpRequestMessage and return a value;
    }
}

然后在个人资料中：

public class ApplicationUserResponseProfile : Profile
{
    public ApplicationUserResponseProfile()
    {
        CreateMap<ApplicationUser, ApplicationUserResponseModel>()
                 .ForMember(dest => dest.Url, opt => opt.MapFrom<YourResolver>());
    }
}

来源：https://docs.automapper.org/en/stable/Dependency-injection.html

- Leandro Carvalho