代码之家 › 专栏 › 技术社区 › pedrommuller

访问要在IValueResolver中映射的目标属性名称

automapper c#

pedrommuller · 技术社区 · 4 年前

我想对同一个类的几个属性重用同一个IValueResolver,要映射的所有三个属性都会传递给同一个进程,所以我不想重复几乎相同的代码。

我想这样做:

CreateMap<AlertLine, AlertLineDto>()
                .ForMember(dest => dest.BusinessArea, opt => opt.MapFrom<MyResolver>())

CreateMap<AlertLine, AlertLineDto>()
                .ForMember(dest => dest.Division, opt => opt.MapFrom<MyResolver>())

CreateMap<AlertLine, AlertLineDto>()
                .ForMember(dest => dest.SubDivision, opt => opt.MapFrom<MyResolver>())


public class MyResolver : IValueResolver<AlertLine, AlertLineDto, string>
    {
        private readonly ICatalogService _catalogService;
        public BusinessAreaResolver(ICatalogService catalogService)
        {
            _catalogService = catalogService;
        }
        public string Resolve(AlertLine source, AlertLineDto destination, string destMember, ResolutionContext context)
        {
            // How to access the destination property name to be mapped?
            // BusinessArea, Division, SubDivision, and so on...

            string val = string.Empty;
            var variant = JsonSerializer.Deserialize<AddlInformation>(source.AddlDimension);
            if (variant.BUSINESS_AREA_ID > 0)
            {
                var businessArea = _catalogService.GetCachedBusinessAreaById(variant.BUSINESS_AREA_ID);
                val = businessArea?.Description;

            }
            return val;
        }

    }

0 回复 | 直到 4 年前

Akshay G 4 年前

尝试使用 IMemberValueResolver 而不是 IValueResolver

如果不同成员的逻辑不同,则发送属性名而不是实际的源值。

CreateMap<AlertLine, AlertLineDto>()
.ForMember(
    dest => dest.BusinessArea,
    opt => opt.MapFrom<MyResolver, string>(p => "BusinessArea"))) 
    //opt => opt.MapFrom<MyResolver, string>(source => source.BusinessArea))
.ForMember(
    dest => dest.Division,
    opt => opt.MapFrom<MyResolver, string>(p => "Division")))
   //opt => opt.MapFrom<MyResolver, string>(source => source.Division))
.ForMember(
    dest => dest.SubDivision,
    opt => opt.MapFrom<MyResolver, string>(p => "SubDivision"));
    //opt => opt.MapFrom<MyResolver, string>(source => source.SubDivision))

这个 propertyName 参数将帮助您根据参数的值确定当前调用的映射。这个 returnValue 将映射到相应的目标成员

public class MyResolver : IMemberValueResolver<AlertLine, AlertLineDto, string, string>
{    
    public string Resolve(AlertLine source, AlertLineDto destination, string propertyName, string destMember, ResolutionContext context)
    {
        string sourceValue = string.Empty;
        string returnValue = string.Empty;

        switch (propertyName)
        {
            case "BusinessArea":
                 sourceValue = source.BusinessArea;
                 //returnValue = Some Logic here
                break;
            case "Division":
                sourceValue = source.Division;
                //returnValue = Some Logic here
                break;
            case "SubDivision":
                sourceValue = source.SubDivision;
                //returnValue = Some Logic here
                break;

            default:
                break;
        }          
        return returnValue;
    }    
}