c# - Automapper 在 Profile 类中注入(inject) DbContext

Question

我有以下映射配置文件

public class DomainProfile : Profile
{
    private FootballPredictionsContext m_Context;

    public DomainProfile(FootballPredictionsContext context)
    {
        m_Context = context;
    }

    public DomainProfile()
    {
        CreateMap<TipModel, Tip>()
            .ForMember(tip => tip.BetType, m => m.MapFrom(x => m_Context.BetTypes.First(y => y.Name == x.BetType)))
            .ForMember(tip => tip.BetCategory, m => m.MapFrom(x => m_Context.BetCategories.First(y => y.Name == x.BetCategory)))
            .ForMember(tip => tip.Sport, m => m.MapFrom(x => m_Context.Sports.First(y => y.Name == x.Sport)))
            .ForMember(tip => tip.Tipster, m => m.MapFrom(model => m_Context.Tipsters.First(y => y.Username == model.Tipster)));
    }
}

如您所见，一些映射正在使用 DbContext，因此我必须以某种方式将其注入(inject) DomainProfile

在 Startup 类中，我正常初始化 Automapper

public void ConfigureServices(IServiceCollection services)
        {
            services.AddScoped(typeof(IUnificator), typeof(Unificator));
            services.AddDbContext<FootballPredictionsContext>(options => options.UseSqlServer(Configuration.GetConnectionString("Database")));
            services.AddDbContext<UnificationContext>(options => options.UseSqlServer(Configuration.GetConnectionString("Database")));

            services.AddSingleton(provider => new MapperConfiguration(cfg =>
                {
                    cfg.AddProfile(new UserProfile(provider.GetService<IUserManager>()));
                }).CreateMapper());
            services.AddMvc();
        }

我试过了 this解决方案，但我收到了 “无法解析来自根提供商的作用域服务‘FootballPredictions.DAL.FootballPredictionsContext’。”

Answer 1

我最近遇到了一个类似的问题，这是因为我试图将一个服务注入(inject)到一个生命周期更长的服务中(例如 transient 和作用域)。与 DomainProfile 类关联的生命周期是多少？您是否尝试过将其更改为 Scoped 或 Transient 以查看是否有帮助？

由@DimitarTsonev 实现:因此，将映射器范围更改为

services.AddScoped(provider => new MapperConfiguration(cfg =>
    {
        cfg.AddProfile(new DomainProfile(provider.GetService<FootballPredictionsContext>()));
    }).CreateMapper());

解决了问题