如何从泛型类或方法的成员获取 T 的类型 [英] How to get the type of T from a member of a generic class or method

问题描述

假设我在类或方法中有一个通用成员，如下所示:

Let's say I have a generic member in a class or method, like so:

public class Foo<T>
{
    public List<T> Bar { get; set; }
    
    public void Baz()
    {
        // get type of T
    }   
}

当我实例化该类时，T 变为 MyTypeObject1，因此该类具有通用列表属性:List.这同样适用于非泛型类中的泛型方法:

When I instantiate the class, the T becomes MyTypeObject1, so the class has a generic list property: List<MyTypeObject1>. The same applies to a generic method in a non-generic class:

public class Foo
{
    public void Bar<T>()
    {
        var baz = new List<T>();
        
        // get type of T
    }
}

我想知道我的类列表包含什么类型的对象.那么名为 Bar 的列表属性或局部变量 baz 包含什么类型的 T 呢?

I would like to know what type of objects the list of my class contains. So what type of T does the list property called Bar or the local variable baz contain?

我不能做 Bar[0].GetType()，因为列表可能包含零个元素.我该怎么做?

I cannot do Bar[0].GetType(), because the list might contain zero elements. How can I do it?

推荐答案

如果我理解正确，您的列表与容器类本身具有相同的类型参数.如果是这种情况，则:

If I understand correctly, your list has the same type parameter as the container class itself. If this is the case, then:

Type typeParameterType = typeof(T);

如果您幸运地将 object 作为类型参数，请参阅 Marc 的回答.

If you are in the lucky situation of having object as a type parameter, see Marc's answer.

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