Fichas
Android Interview Questions
Fichas del conjunto (23)
- 1What are the 4 Java classes related to the use of SENSORS in android?1. sensor
2. SensorManager
3. SensorEvent
4. SensorEventListener - 2Describe sensorProvides methods to identify which capabilities are available for a specific sensor.
- 3Describe SensorManager?Provides methods for registering sensor event listeners and calibrating sensors.
- 4Describe SensorEvent?Provides raw sensor data, including info regarding accuracy
- 5Describe sensorEventListeners?interface that defines callback methods that will receive sensor event notifications
- 6What is ContentProvider?Manages access to a structured set of data, it encapsulates the data and provides mechanisms for for defining data security
- 7What is ContentProvider used for?It is the standard interface that connects data in one process with code running in another process.
- 8Describe 3 common uses cases for using an intent?1. start an activity
2. start a service
3. start a broadcast - 9If the view values in a program do not reset after a screen reorientation, what would be the bare minimum to check?Verify that it has a valid "ID", each view must have a unique ID via "android:id"
- 10What is DDMS?Dalvik Debug Monitor Server
- 11What are some capabilities of the DDMS?- port forwarding services
- screen capture
- thread and heap info
- network traffic tracking
- incoming call and SMS spoofing
- simulate network speed, latency, and state
- location data spoofing - 12What is an Intent?object used for starting a new activity, and transferring data from one activity to another
- 13Can an Intent be used to provide data to a ContentProvider?We cannot start a ContentProvider with an Intent.
To access data in "ContentProvider", we must use "ContentResolver" object to communicate with the provider as a client. "ContentResolver" object communicates with the provider object - 14What is serializable in Android?A standard Java interface. We mark a class serializable by implementing the interface, Java will auto serialize in certain situations
- 15What is Parseable in Android?A Android specific interface, where we implement serialization by ourselves.
- 16What is Service in Android?Is the base class for Android services. Classes that directly extend the Service class runs on the Main Thread so should be used for short tasks.
- 17What is IntentService in Android ?Subclass of service, that handles Async requests on demand. Clients send through (startService(intent)) calls
- 18How do you supply construction arguments into a fragment?Construction Arguments are passed via "Bundle"
-Fragment#setArgument() to set args
-Fragment#getArguments() to get args in appropriate fragment lifecycle methods - 19What is ANR?"Application Not Responding"
When user is interacting with the "Activity", while activity is in onResume(), a dialog will appear stating ANR - 20Why does ANR happen?Happens when we start a heavy and long running task in the Main Thread. Should run these tasks in the Async way
- 21Which method is called only once in a Fragment lifecycle?onAttached()
- 22Is it possible to create an Activity in Android without a user interface?Yes. These activities are treated as abstract activities
- 23What is broadcast receiver?They communicate with the operation system messages, ex "Check internet connection", what battery label should be