>>如何更改此行为，以便MEF释放那些对象?

似乎有三种方法可以解决此问题，建议您参考下面的链接，以检查它是否对您有用.

#MEF保留对非共享IDisposposable部件的引用，不允许它们由GC收集

根据您的描述，它似乎与调用服务时的MEF创建对象有关.我建议您尝试通过一个包含MEF的小项目来重现您的问题，然后我们可以与您紧密合作 通过这个项目.

Based on your description, it seems it is related with the MEF create objects when services are called. I would suggest you try to reproduce your issue with a small project which contains MEF, and then we could work closely with your issue by this project.

***的问候

爱德华