Describe Android Application Architecture.

Correct Answer: - AIDL is the abbreviation for Android Interface Definition Language - It handles the interface requirements between a client and a service to communicate at the same level through interprocess communication - The process involves breaking down objects into primitives that are Android understandable AIDL supports following data types: - String - List - Map - CharSequence - All native Java data types like int,long, char and Boolean

Correct Answer: - Notification messages to the user from an Android enabled device can be displayed using Intents - There are two types of Intents - Explicit Intent, Implicit Intent Implicit Intent: - In case of Implicit Intent, an intent is just declared - It is for the platform to find an activity that can respond to it - Since the target component is not declared, it is used for activating components of other applications Explicit Intent - Explicit intent specifies the particular activity that should respond to the intent - They are used for application internal messages

Correct Answer: A call to onStop method happens when an activity is no longer visible to the user, either because another activity has taken over or if in front of that activity

Correct Answer: Yes, it is possible to do that, such as when you want to create a background behavior for a particular activity You can do this by using add(Fragment,string) method to add a fragment from the activity

Correct Answer: The foreground activity, being the most important among the other states, is only killed or terminated as a last resort, especially if it is already consuming too much memory When a memory paging state has been reach by a foreground activity, then it is killed so that the user interface can retain its responsiveness to the user

Correct Answer: Specify android id, layout height and width as depicted in the following example

Correct Answer: Android uses Dalvik Virtual Machine (DVM) which requires a special bytecode We need to convert Java class files into Dalvik Executable files using an Android tool called "dx" In normal circumstances, developers will not be using this tool directly and build tools will care for the generation of DVM compatible files

Correct Answer: Each application gets its own Linux user ID and virtual machine which means that the application code runs in isolation from other applications

Correct Answer: TelephonyManager class can be used to get the IMEI number It provides access to information about the telephony services on the device Code TelephonyManager mTelephonyMgr = (TelephonyManager) getSystemService(ContextTELEPHONY_SERVICE); String imei = mTelephonyMgrgetDeviceId();

Correct Answer: Intents are created to define an action that we want to perform and the launches the appropriate activity from another application Code Intent intent = new Intent(IntentACTION_SEND); intentputExtra(IntentEXTRA_EMAIL, recipientArray); startActivity(intent);