Android Core Building Blocks

All Android application continue running and in memory until the system needs resources for other application. A main four components of Android Application use the application manifest file AndroidManifest.xml describes each component.

Android Application Components
  • Activities
  • Services
  • Broadcast Receivers
  • Content Providers
  • Intent

Activities

Activity processes have application components the user is interacting with. Its represents the presentation layer of an Android application. Its presents screen in your application.

Services

Android offers the Service class to create application components that handle long-lived aperation and include functionality that doesn't require a user interface.

Services are started, stopped and controlled from other application components, including Activities, Broadcast Receivers, and other Services.

Intent

Intent are used as a message-passing mechanism that both within your application and between application

  • Starts a particular Service are Activity using a class name.
  • Start an Activity or Service to platform an action with a particular piece of data.
  • Broadcast that an event has occurred

BroadCast Reciever


Broadcast Intents are used to notify application of system or application events, extending the event-driven programming model between applications.

Within your application, construct the intent you want to broadcast and call send Broadcast to send it .

Content Providers


Content Providers provide a interface for publishing and the content:// schema. Content Providers can be shared between applications, queried for results, have their existing record deleted or updated, and record added.