Xamarin Certification Xamarin Data and Services 2

Question 1

What is the purpose of Xamarin.Essentials Preferences API?

Accepted Answer

Stores simple key-value pairs persistently using platform-native storage

Answer

Preferences provides a cross-platform API for reading and writing persistent key-value data, backed by NSUserDefaults on iOS and SharedPreferences on Android.

Question 2

Which Xamarin.Essentials class allows accessing the device's file system paths cross-platform?

Accepted Answer

FileSystem

Answer

FileSystem provides cross-platform access to AppDataDirectory and CacheDirectory without needing platform-specific code.

Question 3

In Xamarin, what does the Repository pattern provide when working with data sources?

Accepted Answer

An abstraction over data access logic, separating business logic from data source details

Answer

The Repository pattern abstracts database or API calls behind an interface, making the data layer swappable and the business logic testable.

Question 4

Which Azure service is commonly integrated with Xamarin apps for backend data sync and offline support?

Accepted Answer

Azure Mobile Apps (Easy Tables)

Answer

Azure Mobile Apps provides an offline sync SDK for Xamarin that caches data locally and syncs with the backend when connectivity is restored.

Question 5

In Xamarin, what does the Retry Pattern help with when calling remote services?

Accepted Answer

Automatically retrying failed transient network requests with backoff

Answer

The Retry Pattern handles transient failures (timeouts, momentary connectivity loss) by retrying the operation with exponential backoff.

Xamarin Certification Practice Test

Xamarin Certification Practice Test

Xamarin Certification Xamarin Data and Services 2