ValueInjecter - 递归映射

时间:2011-04-05 18:30:39

标签: automapping valueinjecter

我对自动映射很新,甚至比ValueInjecter更新。如果这是一个简单的问题,我很抱歉,但我似乎无法在任何地方找到答案。

我如何进行递归映射?例如,这是我当前的工厂方法,它将Subject(从我的数据服务)映射到SubjectViewModel:

private SubjectViewModel createSubject(DataService.SubjectResult s) {
    SubjectViewModel result = new SubjectViewModel();
    result.SubjectName = s.SubjectName;
    result.id = s.id;

    foreach (DataService.SubjectResult sChild in s.Children)
        result.ChildSubjects.Add(createSubject(sChild));

    return result;
}

我猜这对于ValueInjecter来说是一种千载难逢的情况,所以如果有人能指出我正确的方向,我会很感激!

这是一个虚假但完整的代码示例:

[TestClass]
public class UnitTest1 {

    [TestMethod]
    public void TestMethod1() {
        Subject S = new Subject() {
            id = 1,
            SubjectName = "S1", Children = { new Subject() { id = 2, SubjectName = "S1a" },
                                             new Subject() { id = 3, SubjectName = "S1b" }}
        };

        SubjectViewModel VM = new SubjectViewModel();
        VM.InjectFrom<CollectionToCollection>(S);

        Assert.AreEqual(2, VM.Children.Count);
    }
}


public class Subject {
    public Subject() {
        Children = new List<Subject>();
    }

    public string SubjectName { get; set; }
    public int id { get; set; }

    public List<Subject> Children { get; private set; }
}

public class SubjectViewModel {
    public SubjectViewModel() {
        Children = new List<SubjectViewModel>();
    }

    public string SubjectName { get; set; }
    public int id { get; set; }

    public List<SubjectViewModel> Children { get; set; }
}

public class CollectionToCollection : Omu.ValueInjecter.ConventionInjection {
    protected override bool Match(ConventionInfo c) {
        return c.SourceProp.Name == "Children";
    }

    protected override object SetValue(ConventionInfo c) {
        List<SubjectViewModel> result = new List<SubjectViewModel>();
        foreach (Subject S in (c.SourceProp.Value as IEnumerable<Subject>))
            result.Add(new SubjectViewModel());
        return result;
    }
}

编辑 - 我知道这是一种天真的方法,这不是递归的。现在我只是试图在没有例外的情况下实现这一目标

现在我得到:

  

System.ArgumentException:对象   类型   'System.Collections.Generic.List`1 [TestValueInjector.SubjectViewModel]'   无法转换为类型   'System.String'。

1 个答案:

答案 0 :(得分:2)

您收到此错误的原因是因为您将源属性Children与目标对象中的所有属性进行匹配,因此将为所有匹配调用SetValue。

你需要的是:

protected override bool Match(ConventionInfo c)
{
   return c.SourceProp.Name == c.TargetProp.Name 
          && c.SourceProp.Name == "Children";
}