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MEF attribute-free approach: lazy initialization by condition

My previous post contains attempt use attribute-free (convention based) approach to configure MEF: MEF 2: import many.
But it contains export metadata attribute usage in the class PluginMetadataAttribute needed for lazy initialization plugin by condition (specific name, version).
How to get rid of ExportAttribute dependency?

Solution

  • The An Attribute-Free Approach to Configuring MEF article that you reference in your other question includes an example on how to add metadata without using an attribute.

    The example shows a use of the PartBuilder.ExportProperties overload that takes an Action<PropertyInfo, ExportBuilder> as a parameter and use one of the ExportBuilder.AddMetadata overloads to add metadata for the specific export.

    This is not the only way to add metadata. All export methods of PartBuilder have an overload that take an Action<> (or an Action<,>) with an ExportBuilder param. You can use these overloads and add your metadata in a similar way.