设计模式中的单键模式，源代码。初学者很有帮助，。-Design Patterns in one-button model, the source code. Beginners helpful.

Singleton设计模式是一个非常有用的机制，可用于在面向对象的应用程序中提供单个访问点-Singleton design pattern is a very useful mechanism that can be used in object-oriented application that provides a single access point