在C＃中使用反射来获得一个嵌套对象的属性 [英] Using reflection in C# to get properties of a nested object

问题描述

由于以下对象：

public class Customer {
    public String Name { get; set; }
    public String Address { get; set; }
}

public class Invoice {
    public String ID { get; set; }
    public DateTime Date { get; set; }
    public Customer BillTo { get; set; }
}

我想使用反射去通过发票来得到一个在名称属性客户。下面是我后，假设这code将工作：

I'd like to use reflection to go through the Invoice to get the Name property of a Customer. Here's what I'm after, assuming this code would work:

Invoice inv = GetDesiredInvoice();  // magic method to get an invoice
PropertyInfo info = inv.GetType().GetProperty("BillTo.Address");
Object val = info.GetValue(inv, null);

当然，这种失败，因为BillTo.Address不是发票类的有效属性。

于是，我试着写一个方法将字符串分割成块的时期，走在寻找终值我感兴趣的对象它的工作好，但我不与它完全满意。

So, I tried writing a method to split the string into pieces on the period, and walk the objects looking for the final value I was interested in. It works okay, but I'm not entirely comfortable with it:

public Object GetPropValue(String name, Object obj) {
    foreach (String part in name.Split('.')) {
        if (obj == null) { return null; }

        Type type = obj.GetType();
        PropertyInfo info = type.GetProperty(part);
        if (info == null) { return null; }

        obj = info.GetValue(obj, null);
    }
    return obj;
}

如何改进这种方法，或者更好的办法来解决这个问题的任何想法？

Any ideas on how to improve this method, or a better way to solve this problem?

修改发布之后，我看到了一些相关的职位......似乎没有被专门解决这个问题的答案，但是。另外，我还是想对我实施的反馈信息。

EDIT after posting, I saw a few related posts... There doesn't seem to be an answer that specifically addresses this question, however. Also, I'd still like the feedback on my implementation.

推荐答案

其实，我觉得你的逻辑是罚款。就个人而言，我可能会改变它周围，所以你传递对象作为第一个参数（这是比较内嵌PropertyInfo.GetValue，所以没那么令人惊讶）。

I actually think your logic is fine. Personally, I would probably change it around so you pass the object as the first parameter (which is more inline with PropertyInfo.GetValue, so less surprising).

我也可能会调用它更像是GetNestedPropertyValue，使之明显，它搜索下来的财产堆栈。

I also would probably call it something more like GetNestedPropertyValue, to make it obvious that it searches down the property stack.

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