Android-four basic components-< two >

1.Activity

2.BroadcastReceiver (Broadcast receiver):

is a component that focuses on receiving broadcast notification information and responds. such as low power, notification time zone changes, and so on.

An app can have any broadcast receiver.

It does not have a user interface and can initiate an activity to respond to received information, or notification Manager to react.

3.content provider (Data sharing)

It can share data from a program for use by other applications.

This data is stored in the file system or in the SQLite database. Content Resolver Object Query,insert, Up-date method

4.Service

It has no visual user interface, but in the background for a period of time to run, for example: The music player's playback function into a service

The user can do other things and listen to music.

Android-four basic components-< two >