Question

最终，我正在尝试从VehicleViewMOdel-> Vehicle进行映射。来源在下面列出。值得注意的是，每个类的两个属性具有不同的类型。

执行映射的代码

var newVehicle = Mapper.Map<Vehicle>(vehicleData_);

要映射的类的代码公共类VehicleViewModel { 公共VehicleViewModel（） {

    }
    //Fuel Economy is in L/Km
    public float CityFuelEconomy {get;set;}
    public float HighwayFuelEconomy {get;set;}
    public float ListPrice {get;set;}
    public float SoldPrice{get;set;}
    [Required]
    public int ModelForeignKey {get;set;}
    [Required]
    public int DealerForeignKey{get;set;}
    public string Notes{get; set;}
    public string Color{get; set;}
}



public class Vehicle
{
    public Vehicle()
    {

    }
    [Key]
    public int Id {get; set;}
    //Fuel Economy is in L/Km
    public float CityFuelEconomy {get;set;}
    public float HighwayFuelEconomy {get;set;}
    public float ListPrice {get;set;}
    public float SoldPrice{get;set;}
    [ForeignKey("VehicleModelId")]
    public virtual VehicleModels ModelForeignKey {get;set;}
    [ForeignKey("VehicleDealerId")]
    public virtual Dealer DealerForeignKey{get;set;}
    public string Notes{get; set;}
    public string Color{get; set;}
}

要处理不同类型类型的属性映射，我在自动映射器配置（startup.cs）中使用了以下“ formember”

Mapper.Initialize(config =>
        {
            config.CreateMap<VehicleViewModel, Vehicle>()
            .ForMember(dest => dest.DealerForeignKey, opt => opt.MapFrom<DealerResolver>())
            .ForMember(dest => dest.ModelForeignKey, opt => opt.MapFrom<VehicleModelResolver>()).ReverseMap();
        });

提到的解析器（VehicleModelResolver和DealerResolver）仅采用source属性（在这种情况下为thype整数），并为Vehicle.ModelForeignKey和Vehicle.DealerForeignKey返回正确类型的对象

private IVehicleRepository _vehicleRepo;
    public DealerResolver(IVehicleRepository vehicleRepo_)
    {
        _vehicleRepo = vehicleRepo_;
    }

    public Dealer Resolve(VehicleViewModel source, Vehicle destination, Dealer destMember, ResolutionContext context)
    {
        List<Dealer> dealers = _vehicleRepo.GetDealerById(source.DealerForeignKey).ToList();
        return dealers.FirstOrDefault();
    }


public class VehicleModelResolver : IValueResolver<VehicleViewModel, Vehicle, VehicleModels>
{
    private IVehicleRepository _vehicleRepo;
    public VehicleModelResolver(IVehicleRepository vehicleRepo_)
    {
        _vehicleRepo = vehicleRepo_;
    }

    public VehicleModels Resolve(VehicleViewModel source, Vehicle destination, VehicleModels destMember, ResolutionContext context)
    {
        List<VehicleModels> vehModels = _vehicleRepo.GetModelById(source.ModelForeignKey).ToList();
        return vehModels.FirstOrDefault();
    }
}

运行代码时，我看到错误消息“没有为此对象定义无参数构造函数。” 在运行时单步执行代码会发现映射对于所有属性都很好，直到VehicleViewModel.MOdelForeignKey。

关于映射VehicleViewModel.ModelForeignKey-> Vehicle.ModelForeignKey有一些我现在看不到的东西。就像我之前说的，我意识到属性是不同类型的，但是解析器应该注意这一点。有任何想法吗？

更新-对此有建议-DI配置不正确。快速制作了一段视频，详细介绍了问题及其解决方法https://youtu.be/tGU7TjDvSK8

Answer 1

youtu.be/tGU7TjDvSK8

这不是我真正的答案，我只是制作了一段视频以使其变得非常清晰。 -我想感谢Lucian Bargaoanu的真正答案。

自动映射器错误-“没有为此对象定义无参数构造函数”

1 个答案: