JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA V MOBILE APPLICATION DEVELOPMENT Previous Question Paper (February - 2022 - R17)

An Activity is a fundamental component in Android that provides a screen with which users can interact to perform tasks, such as dialing a number, taking a photo, or sending an email. Each activity is implemented as a subclass of the Activity class.

The Activity Lifecycle consists of several callback methods that the system calls as the activity transitions between states:

• onCreate(): Called when the activity is first created. This is where you perform static setup such as creating views and binding data to lists.
• onStart(): Called when the activity becomes visible to the user.
• onResume(): Called when the activity starts interacting with the user. The activity is now at the top of the activity stack.
• onPause(): Called when the system is about to start resuming a different activity. Used to commit unsaved changes or stop animations.
• onStop(): Called when the activity is no longer visible to the user.
• onRestart(): Called after the activity has been stopped, prior to it being started again.
• onDestroy(): The final call received before the activity is destroyed, either because the activity is finishing or the system is reclaiming resources.

An Android Virtual Device (AVD) is an emulator configuration that lets you model an actual device by defining its hardware profile, system image, and storage properties. To create an AVD in Android Studio, follow these steps:

1. Open the AVD Manager by clicking the device icon in the toolbar or navigating to Tools > AVD Manager.
2. Click the Create Virtual Device button.
3. Select a hardware profile (e.g., Pixel 4) from the list and click Next.
4. Select a system image (API level) that matches your project's target SDK. If not downloaded, click the download icon next to the version.
5. Verify the configuration settings, such as AVD Name, orientation, and camera settings.
6. Click Finish to create the device.
7. To run your program, select the created AVD from the device dropdown menu in the toolbar and click the Run button. The emulator will launch the virtual device and install your application package.