Android系统中的应用程序都是用Java开发的。Android NDK使我们能够在android上使用C/C++开发的原生代码。

有两个理由使用NDK: 一是合理的重用现有的代码；二是在程序中某些关键的部分提高执行效率。

-Android system applications are written in Java development. Android NDK allows us to use the C/C++ developed in the android native code. There are two reasons for using the NDK: the reasonable reuse existing code　second is to improve the efficiency of the implementation in some of the key parts in the program.