Xamarin Certification Xamarin Data and Services 3

Question 1

What is the purpose of the Polly library in Xamarin HTTP communication?

Accepted Answer

Provides resilience policies like retry, circuit breaker, and timeout for HTTP calls

Answer

Parses Polyglot API responses

Answer

Manages HTTP connection pooling

Answer

Handles multipart form uploads

Question 2

In Xamarin SQLite-Net, which attribute marks a property as the primary key with auto-increment?

Accepted Answer

[PrimaryKey, AutoIncrement]

Answer

[Identity]

Answer

[Key, DatabaseGenerated]

Answer

[Id, AutoGen]

Question 3

Which method is used to create or open a SQLite database asynchronously using SQLite-Net in Xamarin?

Accepted Answer

new SQLiteAsyncConnection(path)

Answer

SQLiteDatabase.Open(path)

Answer

DatabaseFactory.Create(path)

Answer

SqliteDb.Connect(path)

Question 4

In Xamarin, what is the purpose of the Circuit Breaker pattern in service communication?

Accepted Answer

Stops sending requests to a failing service temporarily to allow recovery

Answer

Encrypts HTTP traffic

Answer

Routes traffic to backup servers

Answer

Compresses request payloads

Question 5

Which Xamarin.Essentials method sends an email using the device's default mail app?

Accepted Answer

Email.ComposeAsync

Answer

MailKit.Send

Answer

EmailManager.Open

Answer

Intent.ActionSendTo

Question 6

In Xamarin, which approach is used to cache HTTP responses to reduce redundant network calls?

Accepted Answer

An HttpClient message handler with a caching layer (e.g., Akavache or MonkeyCache)

Answer

HttpClient built-in cache only

Answer

Platform-specific URL cache only

Answer

Static Dictionary<string,string> fields