Reflection - Getting the generic arguments from a System.Type instance

Question

If I have the following code:

MyType<int> anInstance = new MyType<int>();
Type type = anInstance.GetType();

How can I find out which type argument(s) "anInstance" was instantiated with, by looking at the type variable? Is it possible?

Answer 1

Use Type.GetGenericArguments . For example:

using System;
using System.Collections.Generic;

public class Test
{
    static void Main()
    {
        var dict = new Dictionary<string, int>();

        Type type = dict.GetType();
        Console.WriteLine("Type arguments:");
        foreach (Type arg in type.GetGenericArguments())
        {
            Console.WriteLine("  {0}", arg);
        }
    }
}

Output:

Type arguments:
  System.String
  System.Int32

Answer 2

Use Type.GetGenericArguments(). For example:

using System;
using System.Reflection;

namespace ConsoleApplication1 {
  class Program {
    static void Main(string[] args) {
      MyType<int> anInstance = new MyType<int>();
      Type type = anInstance.GetType();
      foreach (Type t in type.GetGenericArguments())
        Console.WriteLine(t.Name);
      Console.ReadLine();
    }
  }
  public class MyType<T> { }
}

Output: Int32