Activity understanding:
1). Activity: one of the four application components
2). Function: Provide an interface that allows users to operate and interact with them
3). The characteristics of the component: its class must implement a specific interface or inherit
You need to configure the full class name in the configuration file
Its object is not created with new, but automatically created by the system
Its object has a certain life cycle, and its class has a corresponding life cycle callback method
4). Those places where the launch technology is used: (Android)
a. Configure the full class name in the configuration file b. The layout file defines the label c. Display intent: Intent (Contex context, class c )
Intent understanding :
1). Intent: messenger (activity, service, BroadcastReceiver) for communication between the three components
2). Classification: Display: operate the current application's own components
Silver: Components that operate other applications
Use of Intent:
1). Create: