小编moh*_*ari的帖子

我使用结构映射作为 asp.net core 中的 di 容器，当我想解析某些自动映射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 AutomapperProfiles.UserRolesResolver 类型的实例

我还在 Startup 类中配置了 automapper，如下所示：

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