First, the four components of the application
the Activity "
Activity is an interface for Android apps that can be used to view contacts, call and play games.
B. An application typically contains multiple activity.
C. Activity adds various view components through layout management.
D. The view can be rendered by using the Setcontentview (int) method.
the Service "
A. The service runs in the background and is responsible for dealing with things that some users don't see and that have a duration. such as downloading data, playing music and so on.
B. The service does not generate UI and is not visible.
C. All user-implemented service must inherit the service class of the system and register it in the configuration file.
"Content Provider "
A. Data is a private program in Android.
B. Content provider provides a mechanism for data interaction among multiple programs.
C. Content provider exposes a number of standard APIs to manipulate data.
"Broadcast Receiver "
A. Broadcast receiver is responsible for responding to external events.
B. Broadcast receiver does not generate UI and is not visible.
C. All user-implemented broadcast receiver must inherit the Broadcastreceiver class of the system and need to be registered in the program.
D. The application can broadcast its own intent through context.sendbroadcast (). Other programs take time processing through their own broadcast receivers interception.
Ii. Important Objects Intent < four components-three all to intent support >
A. Transfer intent start an activity, startactivity, Startactivityforresult;
B. Transfer intent start a service, StartService, Bindservice;
C. New addition to a broadcast by intent, Sendbroadcast, Sendorderedbroadcast (), Sendstickybroadcast ();
D. Executing a query, contentresolver query ();
Third, other
Launcher&widget
Notification
4. What constitutes our Android app? (Seven bulky)