Activity source code analysis

The essence of an Activity is a Contxt

Context has no parent class

In the source code,Context is the abstract class: public Abstract Class Context

Function description of Context

Interface to global information about an application environment. This is an abstract class whose implementation is provided by the Android system. It allows access to application-specific resources and classes, as well as up-calls for application-level operations such as launching activities, broadcasting and receiving intents, etc.

This is an interface that addresses global information about an application’s environment. This is an abstract class whose implementation is provided by the Android system that allows access to application-specific resources and classes while calling system-level application-specific actions such as launching an Activity, broadcasting, and accepting intEnts.

Provides general abstract operation methods

Broadcast related methods sendBroadcast(Intent Intent) and registerReceiver; StartService startService and bindService bindService.