AutoMapper忽略子集合属性

Question

我试图映射具有子对象的集合,我发现忽略同一类型的对象的()应用到性能子对象上似乎嗯...忽视!

这是一个演示问题的单元测试.

class A
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<B> Children { get; set; }
}

class B
{
    public int Id { get; set; }
    public string Name { get; set; }
}

[TestClass]
public class UnitTest1
{
    [TestInitialize()]
    public void Initialize()
    {
        Mapper.CreateMap<A, A>()
            .ForMember(dest => dest.Id, opt => opt.Ignore());

        Mapper.CreateMap<B, B>()
            .ForMember(dest => dest.Id, opt => opt.Ignore());
    }

    [TestMethod]
    public void TestMethod1()
    {
        A src = new A { Id = 0, Name = "Source", Children = new List<B> { new B { Id = 0, Name = "Child Src" } } };
        A dest = new A { Id = 1, Name = "Dest", Children = new List<B> { new B { Id = 11, Name = "Child Dest" } } };

        Mapper.Map(src, dest);

    }

在Map调用之后,A对象的Id属性仍然是1,正如预期的那样,但子B对象的Id属性从11更改为0.

为什么？

Answer 1

AutoMapper 4.1.1中有几个错误.

首先是关于UseDestinationValue:https://github.com/AutoMapper/AutoMapper/issues/568

其次是关于嵌套集合:https://github.com/AutoMapper/AutoMapper/issues/934

可怕!解决方法是B直接映射您的实例:

Mapper.CreateMap<A, A>()
    .ForMember(dest => dest.Id, opt => opt.Ignore())
    .ForMember(dest => dest.Children, opt => opt.Ignore());

Mapper.CreateMap<B, B>()
    .ForMember(dest => dest.Id, opt => opt.Condition((ResolutionContext src) => false));

并添加其他映射调用:

Mapper.Map(src, dest);
Mapper.Map(src.Children.First(), dest.Children.First()); //example!!!

你可以打电话给Mapper.Map周期:

for (int i = 0; i < src.Children.Count; i++)
{
    var srcChild = src.Children[i];
    var destChild = dest.Children[i];

    Mapper.Map(srcChild, destChild);
}

这将使事情正常.