How to use internal class of another Assembly [duplicate]

Question

I have a third party assembly and I would like to use its Internal class in my new C# project. Is it possible?

Any example would really be appreciated

Answer 1

internal: The type or member can be accessed by any code in the same assembly, but not from another assembly.

You can not use internal classes of other assemblies, the point of using internal access modifier is to make it available just inside the assembly the class defined.

if you have access to the assembly code and you can modify it you can make second assembly as a friend of your current assembly and mark the assembly with following attribute

[assembly: InternalsVisibleTo("name of assembly here")]

if not you can always use reflection but be aware that using reflection on a 3rd party assembly is dangerous because it is subject to change by the vendor. you can also decompile the whole assembly and use part of the code you want if it is possible.

Suppose you have this dll (mytest.dll say):

using System; 

namespace MyTest 
{ 
      internal class MyClass 
      {  
          internal void MyMethod() 
          {  
               Console.WriteLine("Hello from MyTest.MyClass!"); 
          } 
      } 
} 

and you want to create an instance of MyTest.MyClass and then call MyMethod() from another program using reflection. Here's how to do it:

using System; 
using System.Reflection;

namespace MyProgram 
{ 
    class MyProgram 
    { 
          static void Main() 
          { 
              Assembly assembly = Assembly.LoadFrom("mytest.dll");
              object mc = assembly.CreateInstance("MyTest.MyClass");
              Type t = mc.GetType(); 
              BindingFlags bf = BindingFlags.Instance |  BindingFlags.NonPublic;
              MethodInfo mi = t.GetMethod("MyMethod", bf); 
              mi.Invoke(mc, null); 
              Console.ReadKey(); 
         } 
    } 
}