# AutoMapper
###### tags: `實作功能`

## 懶人宣告法
### Controller

public SomeContoller(){
    // 讀取所有 Profile !! 少量時可以用，懶起來～ 如果太多有效能問題
    IMapper Mapper = new MapperConfiguration(cfg => cfg.AddMaps(Assembly.GetExecutingAssembly())).CreateMapper();
}

### Profile (SomeProfile.cs)

internal class SomeProfile : Profile
{
    public SomeProfile()
    {
        CreateMap<ViewModel, Model>();
        CreateMap<Model, ViewModel>();
    }
}

---

## ReverseMap 反向(雙向映射)
### 寫法

CreateMap<ViewModel, Model>().ReverseMap();

### 效果等同於

CreateMap<ViewModel, Model>();
CreateMap<Model, ViewModel>();

## 針對 EF
需注意：
* 針對 EF 的 Class 轉換會有異常，需要每個欄位都配置
* 針對 EF 的清單轉換( Ex. List<AAA> To DBSet<AAA> ) 會有異常，因為 EF 的 DBSet 中有些隱藏欄位 ( Ex. 資料是否有被異動 ... )

IMapper mapper = new MapperConfiguration(cfg =>
            {
                cfg.AddMapping<VMC_Customer, Customers>()
                    .ForMember(dst => dst.xxx, opt => opt.MapFrom(src => src.yyy)) MapperConfiguration

                    .ForAllOtherMembers void
                    .ForAllMembers(opt => opt.Condition((src, dst, srcMember, dstMember) => srcMember != null)) void;
            }).CreateMapper(); 

return mapper.Map<VMC_Customer, Customers>(ViewModel);

---

## 配置過濾 null 的值 ( null 的值就不 mapping 過去 )

.ForAllMembers(opt => opt.Condition((src, dst, srcMember, dstMember) => srcMember != null));