设计模式（Design pattern）是一套被反复使用、多数人知晓的、经过分类编目的、代码设计经验的总结。使用设计模式是为了可重用代码、让代码更容易被他人理解、保证代码可靠性。 毫无疑问，设计模式于己于他人于系统都是多赢的，设计模式使代码编制真正工程化，设计模式是软件工程的基石，如同大厦的一块块砖石一样。 -Design patterns (Design pattern) is set to be used repeatedly, most people know, after cataloging, code design experience summary. The use of design patterns to reusable code, so the code is more easily understood by others to ensure code reliability. There is no doubt that the design patterns, design patterns have on others in the system is a win-win, to make the code the preparation of real engineering design mode is the cornerstone of software engineering, as a piece of brick and stone building.