Android mobile application foundation tutorial [Android event handling]

在基于监听的事件处理模型中，事件监听器必须实现事件监听器接口，
Android系统为不同的界面组件提供了不同的监听器接口，
这些接口通常以内部类的形式存在。以View类为例，它包含了一些内部接口，
如 View.OnClickListener、 View.OnLongClickListener、
View.onFocuschangelistener、View.OnKeyListener、View.OnTouchListener。

This chapter mainly explains Android event processing, and explains in detail the event processing of callback mechanism, event processing of monitoring interface mechanism, creation of gesture, export of gesture, drawing gesture and handler message processing. These events are often used in Android program development, so beginners need to master them to facilitate the subsequent development of Android projects.