C# – How to get the type of T from a member of a generic class or method

.netc++generics

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
    }   
}

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
    }
}

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?

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

Best Solution

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);

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