In order to export your QueryEngine
type you should be doing the following
[Export(typeof(IQueryEngine))]
public class QueryEngine : QueryEngine
Now in the plugin class importing it should be as simple as
[Import(typeof(IQueryEngine), RequiredCreationPolicy = CreationPolicy.Shared)]
public IQueryEngine QueryEngine
{
get { return _queryEngine; }
set
{
_queryEngine = value;
}
}
I'm not quite sure what you are attempting to do with the [Export]
on the IQueryEngine
field. You should be able to delete that entirely