匿名类型 - 有什么可区别的特点？ [英] Anonymous Types - Are there any distingushing characteristics?

问题描述

这有什么用，来确定一个类型实际上是匿名类型？例如，一个接口等？

Is there anything to use, to determine if a type is actually a anonymous type? For example an interface, etc?

我们的目标是建立类似如下...

The goal is to create something like the following...

//defined like...
public static T Get<T>(this IAnonymous obj, string prop) {
    return (T)obj.GetType().GetProperty(prop).GetValue(obj, null);
}
//...

//And then used like...
var something = new { name = "John", age = 25 };
int age = something.Get<int>("age");

或者是一个匿名类型的只是美丽？因为它需要一个新的形状没有什么，以确定它的自我？

Or is that just the beauty of an anonymous type? Nothing to identify it self because it takes a new shape?

注意 - 我知道，你可以写在对象类的扩展方法，但似乎有点矫枉过正，在我看来

Note - I realize that you can write an extension method for the object class, but that seems like a little overkill, in my opinion.

推荐答案

编辑：下面的列表适用于C＃匿名类型。 VB.NET具有不同的规则 - 特别是，它可以产生可变的匿名类型（并执行默认情况下）。贾里德指出，该命名风格不同，太注释。基本上，这是所有pretty的脆弱......

The list below applies to C# anonymous types. VB.NET has different rules - in particular, it can generate mutable anonymous types (and does by default). Jared has pointed out in the comment that the naming style is different, too. Basically this is all pretty fragile...

您不能确定它在一个通用的约束，但是：

You can't identify it in a generic constraint, but:

• 这将是一个类（而不是接口，枚举，结构等）
• 这将有<一个href="http://msdn.microsoft.com/en-us/library/system.runtime.compilerservices.compilergeneratedattribute.aspx">CompilerGeneratedAttribute适用于它
• 这将重载Equals，GetHash code和toString
• 这将是在全局命名空间
• 在它不会被嵌套在另一个类型
• 这将是内部的
• 将被密封
• 这将直接来源于对象
• 这将是通用与许多类型的参数性能。 （您的可以的具有非一般的匿名类型，没有属性，这是一个有点意义，但。）
• 在每个属性都会有一个名字，包括属性名称的类型参数，并且将这种类型的参数，例如中Name属性变型℃的财产;> _​​姓名
• 每个属性都将是公开的，只读
• 对于每个属性都会有相应的只读私人领域
• ，将没有其它属性或字段
• 将有一个构造采取对应于每种类型的参数的一个参数，以相同的顺序作为类型参数
• 每个方法和属性将有<一个href="http://msdn.microsoft.com/en-us/library/system.diagnostics.debuggerhiddenattribute.aspx">DebuggerHiddenAttribute适用于它。
• 该类型的名称将开始与＆LT;>和遏制AnonymousType

• It will be a class (rather than interface, enum, struct etc)
• It will have the CompilerGeneratedAttribute applied to it
• It will override Equals, GetHashCode and ToString
• It will be in the global namespace
• It will not be nested in another type
• It will be internal
• It will be sealed
• It will derive directly from object
• It will be generic with as many type parameters as properties. (You can have a non-generic anonymous type, with no properties. It's a bit pointless though.)
• Each property will have a type parameter with a name including the property name, and will be of that type parameter, e.g. the Name property becomes a property of type <>_Name
• Each property will be public and read-only
• For each property there will be a corresponding readonly private field
• There will be no other properties or fields
• There will be a constructor taking one parameter corresponding to each type parameter, in the same order as the type parameters
• Each method and property will have the DebuggerHiddenAttribute applied to it.
• The name of the type will start with "<>" and contain "AnonymousType"

很少的，这是由规范但保证， - 因此它可以在编译器的下一个版本的所有变化，或者如果您使用单声道等

Very little of this is guaranteed by the specification, however - so it could all change in the next version of the compiler, or if you use Mono etc.

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