Automapper 链/嵌套对象映射抛出异常

Question

我在 .NET CORE 5 项目中使用 AutoMapper 版本 10.1.1。我有嵌套的对象，我需要映射但无法这样做并得到以下异常，尽管我可以为第一个孩子映射数据，在我的情况下为“强制”但无法访问子对象“违规”的孩子

0 级课程

 public class SiteContraventionDataView
{
    public int SiteId { get; set; }

    public string SiteName { get; set; }

    public ICollection<EnforcementDataView> Enforcements { get; set; }

}

1 级儿童班

public class EnforcementDataView
{
    public int EnforcementId { get; set; }

    public ICollection<ContraventionDataView> Contraventions { get; set; }
}

当我尝试从上面的子类设置“Contraventions”的来源时出现错误。我正在尝试使用 lambda 表达式来获取 Contravention 对象引用

 .ForMember(dataView => dataView.Enforcements.Select(x=>x.Contraventions), opt => opt.MapFrom(dataModel => GetContraventions(dataModel.Enforcements.ToList())))

自动映射类

public class SiteContraventionsProfile : Profile
{
    public SiteContraventionsProfile()
    {
        CreateMap<Site, SiteContraventionDataView>()
            .ForMember(dataView => dataView.SiteId, opt => opt.MapFrom(dataModel => dataModel.SiteId))
            .ForMember(dataView => dataView.SiteName, opt => opt.MapFrom(dataModel => dataModel.SiteName))
            .ForMember(dataView => dataView.Enforcements, opt => opt.MapFrom(dataModel => dataModel.Enforcements))
            .ForMember(dataView => dataView.Enforcements.Select(x=>x.Contraventions), opt => opt.MapFrom(dataModel => GetContraventions(dataModel.Enforcements.ToList())))
            ;

       
    }

    private List<Contravention> GetContraventions(List<Enforcement> enforcements)
    {
        List<Contravention> contraventions = new List<Contravention>();

        if (enforcements.Any())
        {
            var t1 = enforcements.Select(x => x.EnforcementContraventions);
        }
        
        return contraventions;
    }
}

Answer 1

尝试为Enforcement 和Contravention 添加映射：

CreateMap<Enforcement, EnforcementDataView>();
CreateMap<Contravention, ContraventionDataView>();
CreateMap<Site, SiteContraventionDataView>();