I’m trying to add plugins to my game and what I’m trying to implement is this:
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Plugins will be either mine or 3rd party’s so I would like a solution where crashing of the plugin would not mean crashing of the main application.
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Methods of plugins are called very often (for example because of drawing of game objects).
What I’ve found so far:
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1) http://www.codeproject.com/KB/cs/pluginsincsharp.aspx – simple concept that seems like it should work nicely. Since plugins are used in my game for every round I would suffice to add the Restart() method and if a plugin is no longer needed Unload() method + GC should take care of that.
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2) http://mef.codeplex.com/Wikipage – Managed Extensibility Framework – my program should work on .NET 3.5 and I don’t want to add any other framework separately I want to write my plugin system myself. Therefore this solution is out of question.
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3) Microsoft provides: http://msdn.microsoft.com/en-us/library/system.addin.aspx but according to a few articles I’ve read it is very complex.
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4) Different AppDomains for plugins. According to Marc Gravell ( Usage of AppDomain in C# ) different AppDomains allow isolation. Unloading of plugins would be easy. What would the performance load be? I need to call methods of plugins very often (to draw objects for example).
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Using Application Domains – http://msdn.microsoft.com/en-us/library/yb506139.aspx
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Could you please comment on my findings? New approaches are also welcomed! Thanks!
You can define a public interface which the plugin’s must implement. Then with the use of reflection you can scan a “plugin” folder for any classes implementing that interface, then create an instance of that class.
From you’re code just work on the interface and call the needed method’s. About crashing, always make sure that calls to the “plugin” interface are always encapsulated in a try/catch block. If an exception occurs you can always dispose the plugin