这是一个在android下进行gpio驱动开发的例子，在这个例子中分别从底层驱动代码到测试程序再到android上的JNI层，然后通过java代码调用APP fr a mework层的接口实现对开发板上led的控制(This is carried out under a gpio android-driven development example, in this case were driven from the bottom to the android code to the test program on the JNI layer, then through the java code to call APP fr a mework layer interface board led to the development of control)