Xamarin Certification Xamarin.Forms 2

Question 1

Which Xamarin.Forms layout arranges children in a single row or column?

Accepted Answer

StackLayout

Answer

StackLayout arranges child views in a single horizontal or vertical line using its Orientation property.

Question 2

What is the purpose of the BindingContext in Xamarin.Forms?

Accepted Answer

Defines the source object for data bindings on a view and its children

Answer

BindingContext sets the default data source that binding expressions on the view and its children resolve against.

Question 3

Which method in the Application class is called when the app goes to the background?

Accepted Answer

OnSleep

Answer

OnSleep is called by the Xamarin.Forms Application class when the application transitions to the background.

Question 4

In Xamarin.Forms Shell, what attribute on a ContentPage registers it as a navigation route?

Accepted Answer

Route

Answer

The Route property (set via Shell.Route or RouteFactory) registers a page as a named destination for Shell navigation.

Question 5

Which interface must a ViewModel implement to notify the UI of property changes in Xamarin.Forms?

Accepted Answer

INotifyPropertyChanged

Answer

INotifyPropertyChanged requires implementing the PropertyChanged event, which the binding engine subscribes to for UI updates.

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