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c#.netc#-4.0mef

C# MEF usage with static classes


I have a static class in my solution which is used to work with various assemblies. I want to link them through MEF, so I made a field in a class.

[Import(typeof(A))]
    static private A _a1;

Then I have a method to which I pass assembly name as an argument:

    public static A LoadPackage(string filePath)
    {
            var catalog = new AggregateCatalog();
            catalog.Catalogs.Add(new AssemblyCatalog(filePath));
            var _container = new CompositionContainer(catalog);
            ???
    }

So is there a way now to import type from assembly specified by filepath?

I can't do:

_container.ComposeParts(this);

since class is `static and neither can I do this

_container.ComposeParts(_a1);

(which might be completely wrong to begin with) since A doesn't have any constructors(so _a1 is null)


Solution

  • Well it turns out that method I was looking for is GetExportedValue (yeah, I overlooked basic functionality):

    static private A _a1;
    
    public static A LoadPackage(string filePath)
    {
            var catalog = new AggregateCatalog();
            catalog.Catalogs.Add(new AssemblyCatalog(filePath));
            var _container = new CompositionContainer(catalog);
            _a1 = _container.GetExportedValue<A>();
    }
    

    And I got my field filled (just in case, I already moved it to another class, and it looks neat and clean now)