I am working with an architecture that has a main program. When this starts it looks in the executing path via reflection for DLL’s that have inherited off a base class. These are the plugins.
When a new requirement for a new project arises typically a new plugin is created. This plugin has the main plugin class and then possibly a number of other classes and windows forms.
The main plugin class has initialize methods but as its a class library there is no program.cs so to speak to wire up dependencies.
Is there a way via an app.config to wire up dependencies or do you think I should avoid using an IOC Container and just have a factory method in the plugin class that wires up the dependencies some how?
The issue is I may not have the ability to change the main application’s code to setup the IOC container
All major IoC containers have the ability to wire up dependencies with app.config or via an assembly discovery mechanism (like you describe). Typically the main application sets up the container, and then defers to the container to find the plugins (which may be configured via configuration or by assembly probing like you describe above).
For SpringFramework.net, as an example of app.config: http://www.springframework.net/doc-latest/reference/html/objects.html#d4e437
For Castle Windsor, an example of assembly probing: http://stw.castleproject.org/Windsor.Installers.ashx