Problems loading assembly dependencies dynamically at run-time

Question

let me try to explain my problem. I'm currently trying to develop a small "plugin-framework" written in .Net (mainly for experimenting a bit). So the idea is to have a main application to which "plugins" can be added by deploying dlls in a specific folder "plugins" of the main application. Everything works fine, the plugins are instantiated properly, however now I'm facing a problem. I have deployed now a plugin "X" that uses additional 3rd-party plugins and so now I have the problem that these additional 3rd-party plugins required by "X" are not found at run-time. My idea is therefore now to add an additional directory "dependencies" where I also deploy all of the needed plugins.

So my first question: How can I load the assemblies into the application domain (given that I know the path to them) s.t. they can be used by my application?

I tried to approach that by doing something like:

AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);

System.Reflection.Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
{
    //find the path to the assembly and then load and return it by
    //return Assembly.Load("pathToDependencies/failedAssembly.dll");
}

The problem is that this event-handler now gets activated having the "Presentation.Zune.dll" in the args variable (I'm using a WPF app). It seems as if that assembly failed loading but the actual problem is another dll.

Can someone suggest me a better way to solve my problem? I hope that I was able to explain my situation sufficiently, otherwise just ask for further clarification.

Thanks, Juri

Answer 1

You can set the probing path of the runtime so it can find the assemblies. Set the probing element in your apps config file.

<configuration>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <probing privatePath="plugins;dependencies"/>
    </assemblyBinding>
  </runtime>
</configuration>