Comparing types of generic lists

I'm trying to compare two IList<T> by their Type. Both lists have the same T and therefore I thought they should have the same type.

In debug-mode in Visual Studio in the tooltip I can read the types of both and it is the same.

But Equals() ant the == Operator return both false.

Can anyone explanin this weired behavior?

Little Example:

class Program
{
    static void Main(string[] args)
    {
        IList<string> list1 = new List<string>();
        IList<string> list2 = new List<string>();

        var type1 = list1.GetType();
        var type2 = typeof(IList<string>);

        if (type1.Equals(type2))
        {
            Console.WriteLine("equal");
        }
        else
   开发者_JS百科     {
            Console.WriteLine("non equal");
        }

        Console.ReadLine();
    }
}

==> non equal

Edit: I coose a bad Example, this one shows the way I was trying to to it.

I'm using .Net 3.5

Yes, you're comparing two types: List<string> and IList<string>. They're not the same type, and I don't know why you'd expect them to be the same.

It's unclear what you're trying to do, but you might want to use Type.IsAssignableFrom. For example, in your example,

Console.WriteLine(type2.IsAssignableFrom(type1));

will print True.

Answer from before the edit...

Unable to reproduce:

using System;
using System.Collections.Generic;

class Test
{
    static void Main()
    {
        IList<string> list1 = new List<string>();
        IList<string> list2 = new List<string>();

        var type1 = list1.GetType();
        var type2 = list2.GetType();

        Console.WriteLine(type1.Equals(type2)); // Prints True
    }
}

Is it possible that in your real code, they're both implementations of IList<string>, but different implementations, e.g.

IList<string> list1 = new List<string>();
IList<string> list2 = new string[5];

That will show the types being different, because one is a List<string> and the other is a string[].

That is because list1 is List<string> ( so type1 is typeof(List<string>) aswell ) and type 2 is typeof(IList<string>). Notice IList<string> vs List<string>. Neither list1 nor list2 is IList<string>, they are List<T>'s, which derives from IList<T>

As mentioned above this is indeed due to the reason that List<string> and IList<string> are not the same type.

If your goal is to determine whether your type implements an interface (i.e. IList<string>) you can do so with reflection:

 if (type1.GetInterfaces().Contains(typeof(IList<string>)))
     Console.WriteLine("type1 implements IList<string>");