AutoMapperMappingException：无法创建.netcore类型的实例

Question

我在asp.net核心中使用Structure map作为我的di容器 当我想解决一些自动播放器解析器中的某些服务时，如下所示：

public class UserRolesResolver : IValueResolver<User, CurrentUserVeiwModel, List<string>>
{
    private readonly AppUserManager _appUserManager;

    public UserRolesResolver(AppUserManager appUserManager)
    {
        _appUserManager = appUserManager;
    }

    public List<string> Resolve(User source, CurrentUserVeiwModel destination, List<string> destMember, ResolutionContext context)
    {
        destination.Roles = AsyncHelpers.RunSync(() => _appUserManager.GetRolesAsync(source)).ToList();
        return destination.Roles;
    }
}

我得到的是

  

AutoMapperMappingException：无法创建类型的实例   AutomapperProfiles.UserRolesResolver

我还在Startup类中配置了automaticpper，如下所示：

 services.AddAutoMapper(x =>
        {
            x.AddProfiles(Assembly.GetAssembly(typeof(OrderProfile)));
            x.ConstructServicesUsing(type=> ServiceProvider.GetRequiredService(type));
        });