.dll file

Please see DLL files. It depends on the type of DLL file. If the DLL is not a Class Library with managed code then the answer is totally different.

hi,

Agree with Vulpes,

you can write youe extension method over methods of .dll file.

you can also extend your dll class using override(virtual) function or method define in dll.

hope this help.

You could (effectively) add instance methods to the public classes exposed by the dll using extension methods.

If you're not familiar with these, then check this article which shows how to add an extension method to the String class:

http://www.c-sharpcorner.com/uploadfile/43e0cb/extension-methods-in-net/