Using a Content Provider to Store and Retrieve Data
This section describes how to store and retrieve data using a content provider implemented by you or anyone else. Android exposes a number of content providers for a wide range of data types, from music and image files to phone numbers. You can see a list of content providers exposed through the convenience classes in the android.provider package. Android's content providers are loosely linked to their clients. Each content provider exposes a unique string a URI identifying the type of data...
Notifications
Out-of-band alerts should always be displayed using the NotificationManager, which allows you to tell the user about something they may be interested in without disrupting what they are currently doing. A notification can be anything from a brief pop-up box informing the user of the new information, through displaying a persistent icon in the status bar, to vibrating, playing sounds, or flashing lights to get the user's attention. In all cases, the user must explicitly shift their focus to the...
Android Architecture
The following diagram shows the major components of the Android operating system. Each section is described in more detail below. Android will ship with a set of core applications including an email client, SMS program, calendar, maps, browser, contacts, and others. All applications are written using the Java programming language.