如何访问通用属性，而不知道封闭式泛型类型 [英] How to access generic property without knowing the closed generic type

问题描述

我有一个泛型类型如下：

I have a generic Type as follows

public class TestGeneric<T>
{
    public T Data { get; set; }
    public TestGeneric(T data)
    {
        this.Data = data;
    }
}

如果我现在有一个对象（这是从哪里来的一些外部源）从中我知道它的类型是一些封闭TestGeneric<>，但我不知道TypeParameter T.现在我需要访问我的对象的数据。问题是，我不能投的对象，因为我不知道到底哪个关闭TestGeneric。

If i have now an object (which is coming from some external source) from which i know that it's type is of some closed TestGeneric<>, but i don't know the TypeParameter T. Now I need to access the Data of my object. Problem is that i can't cast the object, since i don't know exactly to which closed TestGeneric.

我用

// thx to http://stackoverflow.com/questions/457676/c-reflection-check-if-a-class-is-derived-from-a-generic-class
private static bool IsSubclassOfRawGeneric(Type rawGeneric, Type subclass)
{
    while (subclass != typeof(object))
    {
        var cur = subclass.IsGenericType ? subclass.GetGenericTypeDefinition() : subclass;
        if (rawGeneric == cur)
        {
            return true;
        }
        subclass = subclass.BaseType;
    }
    return false;
}

要确保，我的对象是通用型的。有问题的代码如下：

to make sure, my object is of the generic type. The code in question is as follows:

public static void Main()
{
    object myObject = new TestGeneric<string>("test"); // or from another source
    if (IsSubclassOfRawGeneric(typeof(TestGeneric<>), myObject.GetType()))
    {
        // the following gives an InvalidCastException
        // var data = ((TestGeneric<object>)myObject).Data;

        // if i try to access the property with reflection
        // i get an InvalidOperationException
        var dataProperty = typeof(TestGeneric<>).GetProperty("Data");
        object data = dataProperty.GetValue(myObject, new object[] { });
    }
}

我需要的数据，无论其类型（当然，如果我可以要求使用的GetType其类型（）将被罚款，但不是必要的），因为我只是想用的ToString（）转储它的XML。

I need the Data regardless of its type (well, if i could ask for its type using GetType() would be fine, but not necessary) since i just want to dump it in xml using ToString().

任何建议？感谢名单。

推荐答案

您需要知道封闭式泛型类的，然后才能访问它的通用成员。使用 TestGeneric<> 为您提供了开放式的定义，不能在不指定通用参数调用

You need to know the closed type of a generic class before you can access its generic members. The use of TestGeneric<> gives you the open type definition, which cannot be invoked without specifying the generic arguments.

为您获得的属性值的最简单方法是，以反映在直接使用闭式：

The simplest way for you to get the value of the property is to reflect on the closed type in use directly:

public static void Main()
{
    object myObject = new TestGeneric<string>("test"); // or from another source

    var type = myObject.GetType();

    if (IsSubclassOfRawGeneric(typeof(TestGeneric<>), type))
    {
        var dataProperty = type.GetProperty("Data");
        object data = dataProperty.GetValue(myObject, new object[] { });
    }
}

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