钩子函数，是指模拟原始函数的功能与接口，在原始函数执行前、执行后

增加一些特殊功能或检测代码的技术。在更接近系统层次上的技术中，它被称

为HOOK，而在更面向应用的高级开发，一般使用子类继承或切面技术来实现

相同的功能。

本技巧通过动态特性中的“重写”，来实现钩子以及脱钩(unhook )技术。-Hook function, the original function is the analog functions and interfaces, the original function before execution, after performing functions or add some special code detection technology. Closer to the system level of technology, it is called HOOK, while in the more advanced developing application-oriented, generally using subclass inheritance or slice technology to achieve the same functionality. The skills through dynamic characteristics of the " rewrite"　to achieve the hook and decoupling (unhook) technology.