C#, How to use an external file as an optional module?

Here's the story of my question:

I have a .Net (C#) windows application. This app contains a Panel, a Drop Down and a button.

There's a folder named plugins near my executable file (winapp...exe) which i wish it contains my custom program module files. Like (add2digit.moduleextention, add3digit.moduleextention, addNdigit.moduleextention, ...).List of these files will be shown in m开发者_运维技巧y drop down. All these custom module files need to be written in C#, and all have to implement an interface contains one methods { panel:: GetGUI() };

When i change the drop down, i wish to load the selected module GUI into the panel using it's GetUI() method. By this manner i wont need to recompile my code if i developed further modules. Please give me some keywords or solutions which help me figure this problem out.

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You'll need to create an Interface with GetUI() and other methods declared in it and implement that in plugins, then in your main application you should do something like this:

using System.Reflection;
// ...
Assembly assembly = Assembly.LoadFile(file);
yourInterface plugin = (yourInterface)Activator.CreateInstance(Type.GetType(assembly));
// ...
plugin.GetUI(); // or whatever