Automapper - Ignore mapping with condition

问题:

I'm using automapper and I would like to know if it's possible to ignore a mapping of a field when that's null.

That's my code:

.ForMember(dest => dest.BusinessGroup_Id,             opt => opt.MapFrom(src => (int)src.BusinessGroup)) 

• src.BusinessGroup type = "enum"
• dest.BusinessGroup_Id = int

The objective it's to ingore that Mapping if src.BusinessGroup = null.

回答1:

I think NullSubstitute option will do the trick

.ForMember(d => d.BusinessGroup_Id, o => o.MapFrom(s => (int?)s.BusinessGroup)); .ForMember(d => d.BusinessGroup_Id, o => o.NullSubstitute(0)); 

BTW you can write your conditions in mapping action:

.ForMember(d => d.BusinessGroup_Id,            o => o.MapFrom(s => s.BusinessGroup == null ? 0 : (int)s.BusinessGroup));    

UPDATE if you cannot assign some default value to your property, you can just ignore it and map only not nulls:

.ForMember(d => d.BusinessGroup_Id, o => o.Ignore()) .AfterMap((s, d) =>     {         if (s.BusinessGroup != null)             d.BusinessGroup_Id = (int)s.BusinessGroup;     }); 

文章来源: Automapper - Ignore mapping with condition