Question

我有以下示例对象..

  public class ComplexObject
  {
    public string Name { get; set; }
    public SimpleObject Child1 { get; set; }
    public SimpleObject Child2 { get; set; }
  }
  public class SimpleObject : IEquatable< SimpleObject >
  {
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Gender { get; set; }
    public int? Age { get; set; }
  }

使用以下AutoMapper配置

  Mapper.CreateMap<SimpleObject, SimpleObject>()
    .ForAllMembers(expression=>expression.Condition(r=>!r.IsSourceValueNull));

  Mapper.CreateMap<ComplexObject, ComplexObject>()
    .ForAllMembers(expression=>expression.Condition(resolutionContext=>!resolutionContext.IsSourceValueNull));

以及以下NUnit测试...

[SetUp] public void Should_run_before_each_test()
{
  child1 = new SimpleObject { FirstName = "Tom", LastName = "Smith", Age = 34, Gender = "Male" };
  child2 = new SimpleObject { FirstName = "Andy", LastName = "Smith-bob", Age = 21, Gender = "Male" };
}

[ Test ]
public void Should_ignore_null_properties_in_nested_objects()
{
  var source = new ComplexObject()
  {
    Name = "blue",
    Child1 = new SimpleObject{FirstName = "dot", LastName = "net"}
  };
  var destination = new ComplexObject()
  {
    Name = "Andy",
    Child1 = child1,
    Child2 = child2
  };

  destination = Mapper.Map(source, destination);

  destination.Name.Should(Be.EqualTo(source.Name));
  destination.Child1.FirstName.Should(Be.EqualTo("dot"));
  destination.Child1.LastName.Should(Be.EqualTo("net")  );
  destination.Child1.Age.Should(Be.EqualTo(child1.Age)  );
  destination.Child1.Gender.Should(Be.EqualTo(child1.Gender)  );
}

当断言年龄时，上面的测试失败，因为AutoMapper将null推送到目标对象。

我对AutoMapper的期望过高，或者我错过了一些重要的地图配置步骤。

最终目标是通过MVC操作将非常复杂的域对象绑定到传入的表单数据。然后，AutoMapper将用于仅将非空属性（在对象图的所有深度处）合并到整个多步形式中维护的实例中。

以防任何人需要知道...我也尝试了以下映射配置而没有任何运气:(

  Mapper.CreateMap<ComplexObject, ComplexObject>()
    .ForMember(x=>x.Child1, l=>l.ResolveUsing(x=>x.Child1 == null?null:Mapper.Map<SimpleObject,SimpleObject>(x.Child1)))
    .ForMember(x=>x.Child2, l=>l.ResolveUsing(x=>x.Child2 == null?null:Mapper.Map<SimpleObject,SimpleObject>(x.Child2)))
    .ForAllMembers(expression=>expression.Condition(resolutionContext=>!resolutionContext.IsSourceValueNull));

Answer 1

如果源值为null，为什么期望目标对象上的值不为null？ int?的默认值为null，因此，当您致电

时

destination.Child1.Age.Should(Be.EqualTo(child1.Age));

.Should正在失败。这应该是预期的行为。

尝试类似Assert.Null(detination.Child1.Age)的内容，它应该通过。 AutoMapper没有“推动”该值，没有源值，因此，Age将具有默认值。

AutoMapper如果不为Null，则嵌套对象的Map属性

1 个答案: