AutoMapper-将目标字符串设置为null实际上使它成为string.Empty [英] AutoMapper - setting destination string to null actually makes it string.Empty

问题描述

具有以下映射:

Mapper.CreateMap<ObjectA, ObjectB>()
    .ForMember(dest => dest.SomeStringProperty, opt => opt.MapFrom(src => null))

SomeStringProperty现在是空字符串，不为空(正如我期望的那样)

SomeStringProperty is now empty string not null (as I would expect)

这是一个错误吗?我怎样才能使它实际上为空?

Is this a bug? How can I get it to actually be null?

我看到opt.Ignore()会将其设置为null，但实际上我想像下面这样执行条件空值，而上述简化的bug(?)可以防止这种情况

I see that opt.Ignore() will make it null but I actually want to do a conditional null like the following and the above simplified bug(?) is preventing this

Mapper.CreateMap<ObjectA, ObjectB>()
    .ForMember(dest => dest.SomeStringProperty, opt => opt.MapFrom(src => src.SomeOtherProp != null ? src.SomeOtherProp.Prop1 : null))

推荐答案

我在查看源代码后发现了该设置...确认这不是错误，而是实际上是可配置的设置.

I found the setting after looking through the source code... Confirming that this is not a bug, but in fact a configurable setting.

当我配置映射时..

Mapper.Initialize(x =>
{
    x.AddProfile<UIProfile>();
    x.AddProfile<InfrastructureProfile>();
    x.AllowNullDestinationValues = true; // does exactly what it says (false by default)
});

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