如何动态地从一个C＃ExpandoObject通过名称的属性？

问题描述

我有一个 ExpandoObject 并要为此做出一个getter将由名在运行时，其中名称是在字符串中指定的硬编码，而不是返回属性。

I have an ExpandoObject and want to make a getter for it that will return a property by name at runtime, where the name is specified in a string instead of hardcoded.

例如，我可以这样做：

account.features.isEmailEnabled;

和将返回true。 帐户是 ExpandoObject 和功能也是 ExpandoObject 。所以，我有一个 ExpandoObject 包含其他 ExpandoObjects 。

and that will return true. account is a ExpandoObject, and features is also an ExpandoObject. So I have an ExpandoObject that contains other ExpandoObjects.

所以我希望能够做的是这样的：

So what I want to be able to do is this:

account.features.GetProperty("isEmailEnabled");

和有回归真实的。

原因是，我有很多的功能，我希望能够写一个通用的getter方法，我可以在我想要的功能的名称传递，并且该方法将通过我回来了account.features.whatever值（其中，无所谓是通过在字符串传递给普通的getter方法指定）。否则我将不得不写30-一些干将为每个功能

The reason is that I have many features, and I want to be able to write one generic getter method where I can pass in the name of the feature I want, and the method will pass me back the value for account.features.whatever (where "whatever" is specified by passing in a string to the generic getter method). Otherwise I am going to have to write 30-some getters one for each feature.

我做了很多的研究，并试图做这样的事情：

I did a lot of research and tried doing something like:

var prop = account.features.GetType();  
// this returns System.Dyanmic.ExpandoObject

其次

followed by

var value = prop.GetProperty(featureNameAsString); 

但值总是回来空。我不明白为什么。在监视窗口中我可以做 account.features.isEmailEnabled ，它显示了真实和说，它的一个布尔值。但是，如果我尝试使用上面的方法在这个值来获取和传递 isEmailEnabled 为 featureNameAsString 我只是得到空

but value always comes back as null. I don't understand why. In the watch window I can do account.features.isEmailEnabled and it shows true and says its a boolean. But if I try to get at this value using the approach above and pass in isEmailEnabled as the featureNameAsString I just get null.

有人可以告诉我，我可能做错了，什么是一个好办法，没有它太复杂？

Can someone please tell me what I may be doing wrong and what's a good approach, without it being too complex?

我在4.5.1框架下使用ASP.NET。

I am working with ASP.NET under the 4.5.1 framework.

推荐答案

ExpandoObject 既可以通过可访问动态并通过的IDictionary<字符串对象> - 所以，你可以只需使用字典API：

ExpandoObject provides access both via dynamic and via IDictionary<string,object> - so you could just use the dictionary API:

var byName = (IDictionary<string,object>)account.features;
bool val = (bool)byName["isEmailEnabled"];

如果该名称是固定的，只是：

Or if the name is fixed, just:

bool val = ((dynamic)account).features.isEmailEnabled;

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