Android Application Framework

Every Android application runs in a secure sandbox:

1. The system gives each application a UserID that grants operation permissions on all files of the application.

2. Each application creates an independent VM.

 

There are separate methods for activiting each type of component:

• You can start an activity (or give it something new to do) by passingIntentToStartActivity ()OrStartActivityForResult ()(When you want the activity to return a result ).
• You can start a service (or give new instructions to an ongoing service) by passingIntentToStartService (). Or you can bind to the service by passingIntentToBindService ().
• You can initiate a broadcast by passingIntentTo methods likeSendBroadcast (),SendOrderedBroadcast (), OrSendStickyBroadcast ().
• You can perform a query to a content provider by callingQuery ()OnContentResolver.