4
CHAPTER
Application Components
A pplication components are the essential building blocks of an Android application. These components
are loosely coupled by the application manifest file AndroidManifest.xml that describes each component of the
application and how they interact.
There are following four main components that can be used within an Android application:
Components Description
Activities They they dictate the UI and handle the user interaction to the smartphone screen
Services They handle background processing associated with an application.
Broadcast Receivers They handle communication between Android OS and applications.
Content Providers They handle data and database management issues.
Activities
An activity represents a single screen with a user interface. For example, an email application might have one
activity that shows a list of new emails, another activity to compose an email, and another activity for reading
emails. If an application has more than one activity, then one of them should be marked as the activity that is
presented when the application is launched.
An activity is implemented as a subclass of Activity class as follows:
public class MainActivity extends Activity {
}
Services
A service is a component that runs in the background to perform long-running operations. For example, a service
might play music in the background while the user is in a different application, or it might fetch data over the
network without blocking user interaction with an activity.
A service is implemented as a subclass of Service class as follows:
public class MyService extends Service {
TUTORIALS POINT
Simply Easy Learning
CHAPTER
Application Components
A pplication components are the essential building blocks of an Android application. These components
are loosely coupled by the application manifest file AndroidManifest.xml that describes each component of the
application and how they interact.
There are following four main components that can be used within an Android application:
Components Description
Activities They they dictate the UI and handle the user interaction to the smartphone screen
Services They handle background processing associated with an application.
Broadcast Receivers They handle communication between Android OS and applications.
Content Providers They handle data and database management issues.
Activities
An activity represents a single screen with a user interface. For example, an email application might have one
activity that shows a list of new emails, another activity to compose an email, and another activity for reading
emails. If an application has more than one activity, then one of them should be marked as the activity that is
presented when the application is launched.
An activity is implemented as a subclass of Activity class as follows:
public class MainActivity extends Activity {
}
Services
A service is a component that runs in the background to perform long-running operations. For example, a service
might play music in the background while the user is in a different application, or it might fetch data over the
network without blocking user interaction with an activity.
A service is implemented as a subclass of Service class as follows:
public class MyService extends Service {
TUTORIALS POINT
Simply Easy Learning
