Xamarin Interview Questions and Answers

Data Binding is based on MVVM (Model-View-ViewModel) Architecture. It links the properties of two objects. This allows changes in one property to automatically reflect in the other one. It can be implemented either with XAML or with code. It is wise to use it with XAML as it reduces the code-behind file size.

Effects simplify the customization of controls, are reusable, and further parameters can be added in the future to increase its reuse. It allows us to customize the traditional or native controls on each platform. An Effect is recommended when we change the properties of a platform-specific control that is achieving the desired result.

Four events occur during the Xamarin.Forms LifeCycle:

• OnStart event - Startup of an application.
• Suspension - When the Xamarin.Forms come to this event, it got suspended or terminated.
• OnResume event - When the application is resumed from background.
• OnSleep event - When the application goes to background.

There are 5 types of layout control in Xamarin.Forms:

• StackLayout
• Grid
• AbsoluteLayout
• RelativeLayout
• FlexLayout

There are 6 types of pages available in Xamarin Forms: Carousel Page, Content Page, MasterDetail Page, Navigation Page, Tabbed Page, and Template Page.

A resource dictionary is a repository for XAML resources that your application uses, such as styles. You define resources in XAML and retrieve it using two markup extensions. Static and Theme resource. You can also retrieve it using a code.

View to view bindings means linking of the properties of two views on the same page just like data bindings which link properties of two objects, called source and target.

Xamarin Essentials helps developers to establish a single cross-platform API for their mobile applications like Android, iOS, and any UWP applications or Xamarin.Forms that can be accessed from shared code. This library APIs save a lot of time and money for developers and facilitates the rapid prototyping process.

When the Android runtime needs to call managed code, we use Android Callable Wrappers. These wrappers are needed because it is not possible to register classes with Android runtime during a runtime. Thus whenever there is a lack of runtime type registration support needed, Android Callable Wrappers come into play.

They can deliver native iOS, Windows, and Android apps using existing skills, teams, and code(C# XAML).

• With Xamarin technology one can take full advantage of Native APIs. Native controls and behaviors can be mapped with Xamarin.Form elements.
• The app store of Xamarian allows the addition of high-quality components to the app directly from the IDE, including controls, web service API and more.
• Features like PCL/Shared make it very easy for the app developers to share the same code base throughout various projects.