title: GetInterface always return null
body: <p>I try to write a dll and called by a console program, partial coding as below,
  But somehow, I have no idea why the getinterface always return null and then I can't invoke the function inside the dll.</p>
  
  <p>MyDLL.dll</p>
  
  <pre><code>namespace mynamespace
  {
      public interface IMyClass
      {
         void test();
      }
  
      public class MyClass : IMyClass
      {
         public void test()
         {
            // Do Something here
         }
      }
  }
  </code></pre>
  
  <p>App:</p>
  
  <pre><code>class Program
  {
      static void Main(string[] args)
      {            
          List&lt;object&gt; output = new List&lt;object&gt;();
  
          Assembly assembly = Assembly.LoadFile(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "MyDLL.dll"));
  
          foreach (Type t in assembly.GetTypes())
          {
              if (t.IsClass &amp;&amp; !t.IsAbstract &amp;&amp; t.GetInterface("mynamespace.IMyClass") != null)
              {
                  output.Add(Activator.CreateInstance(t));
              }
          }
  
          Console.WriteLine("Log is written successfully. Press any key to exit");
          Console.Read();
      }
  }
  </code></pre>
  
  <p>I don't know why <code>t.GetInterface("mynamespace.IMyClass")</code> always return null?</p>