MEF(Managed Extensibility Framework )可控扩展框架
- MEF provides a standard way for the host application to expose itself and consume external extensions. Extensions, by their nature, can be reused amongst different applications. However, an extension could still be implemented in a way that is application-specific. Extensions themselves can depend on one another and MEF will make sure they are wired together in the correct order (another thing you won't have to worry about).
MEF为主应用系统提供标准的方法以便应用系统向外爆露自己和使用外部扩展功能。扩展本身就是要求在不同的系统中可以被重用。但是扩展也应该可以在特定的应用中被重新实现。扩展本身是依赖于其他部分来实现的，通过使用MEF可以使它们很好的组合在一起。各种扩展之间不用互相担心，他们可以很好的在一起工作。
- MEF offers a set of discovery approaches for your application to locate and load available extensions.
MEF 为你的应用提供了一套发现方法来定位和加载可用的扩展。
- MEF allows tagging extensions with additonal metadata which facilitates rich querying and filtering
MEF允许使用附加的元数据来标示扩展，这样就简化和强大了扩展的查询和过滤。