程序只允许打开唯一实例且所有关联文档都在同一实例内打开的一揽子解决办法，收藏好久的，写程序的时候经常用到其中的方法，其中的方法可以根据需要适当的简化，也能实现唯一实例的方案-　　

A long time, writing a program is often used in one of the program only allowed to open a unique instance and all associated documents are open in the same instance of a package solution, collection, which according to the need for appropriate simplification, can be achieved The only instance of the program