XAMARIN Interview Questions for Freshers and experienced :-
1. What is Xamarin?
Xamarin is a developing technology which is used to build UI for Android, iOS, and Windows operating systems using only CQ.
2. What are the extensions of Xamarin applications?
For Android applications, the extension is .apk and for iOS, it is .app.
3. On what platforms you can work?
Android and iOS are the two most popular operating systems on which I can work.
4. What are the languages that Xamarin support for developing any application?
Xamarin is a cross-platform technology which supports FQ and CQ for application development.
5. In an application where you need to require the calculation of shortest distance, then which algorithm will be used?
In that case, the best algorithm to use is the depth first search algorithm.
6. What are the different ways to make Xamarin apps?
Mainly, there are two ways to get the job done. The first is the Xamarin.forms, and the other one is the traditional Xamarin approach.
7. How to decide which way to use to Xamarin apps?
For all those applications where you either code sharing is the priority rather than unique UI or that need very less custom functionality, then Xamarin.froms can be used. On the other hand, you can use Xamarin native for all those apps where custom UI is the priority or you have to make custom interactions.
8. Do you know about application package modes?
There are two modes to choose from. The first one is the release mode and the other one is debug. Both of them have their own requirements and are used when necessary.
9. Mention the different Xamarin.forms techniques to share codes.
Shared projects and PCL are ways to share codes.
10. Elaborate on the use of page in Xamarin.forms.
The page is an element which covers almost the entire screen and only has one child. For Android, Windows, and iOS, it is an activity, page, and view controller respectively.
11. Tell us about Xamarin.forms pages.
There are several pages in Xamarin.forms and they are used as per their requirements. Some of them are tabbedpage, contentpage, and carouselpage.
12. Explain views.
Views are just another word for widgets. Some of the views are an image, list view, button and label.
13. Can you differentiate between TableView and ListView?
The major difference between the both is that TableView shows data in a horizontal manner whereas ListView shows data in a vertical manner.
14. Why cells are used in Xamarin.forms?
Cells are parts that are specifically created to be attached to TableView or ListView.
15. How editor is different from entry?
The primary motive of both of these features is to assist the user in entering text. However, the major difference is that the editor has several lines and entry has only a single line.
16. Explain data binding.
It is a method where a user interface synchronizes automatically with the data source. It shows all the updates automatically to the user interface. Mainly, it focuses on target as well as the sources.
17. Are you aware of the techniques used in data binding.
Yes, there are four different techniques for data binding. Twoway, oneway, default, and onewaytosource.
18. What do you know about TestFlight?
TeshFlight is a method by which you can best test your applications designed for iOS.
19. Why Hockeyapp is used?
Hockeyapp is a service which is used to test iOS, windows and android apps.
20. Do you know about NuGet?
Yes, NuGet is a package manager of .NET development. It is not just any other manager, but the most widely used one.
21. What are Activities?
Activities offer a platform for the user interface which is graphical and only has one screen.
22. What are Native Apps?
Native apps are those which require specific language for their development. This language can be Java, CQ, or swift.
23. What are Cross-Platform apps?
Cross-platform apps are those which are developed for all the three mobile platforms with a single code base. However, they need personalization in the user interface as per the operating system.
24. What are the reasons to use XAML?
XAML is a language used by developers which helps them in specifying the UI with the help of markup instead of any code.
25. What are the reasons to avoid XAML?
Even though XAML is a great technique, but still it has some disadvantages. The reason why it should be avoided is that it does not has any code. Moreover, you cannot define loops of conditional processing.
26. Define Grid
Grid is a layout control in Xamarin.forms which displays information in columns and rows.
27. What is ContentPresenter?
ContentPresenter is used to view templates. It helps in managing how the content appears.
28. What is padding property?
Padding is always added from the internal part of the element and directly affects the content away from the edges.
29. What is margin property?
Margin is the opposite of padding which is executed from the outside of the element and affects how distant the content is from other contents.
30. Mention situations where you can use data binding.
Data mining has different scenarios where it can be used. Model binding, collection binding, and backward binding are some of the scenarios.
31. Xamarin history?
- Xamarin is a Microsoft-owned San Francisco, California based software company founded in May 2011 by the engineers that created Mono, Mono for Android and MonoTouch .
- Novell had granted a perpetual license for Mono on july 2011 for MONO
- On May 16, 2011: Miguel de Icaza announced on his blog that Mono would be developed and supported by Xamarin,
- December 2012, Xamarin released Xamarin.Mac which allows developers to build C#-based applications for the Apple OS X operating system and package them for publishing via the Apple App Store.
- Xamarin 2.0 was released in February 2013 Xamarin.Android and Xamarin.iOS that make it possible to do native Android, iOS and Windows development in C#, with either Visual Studio or Xamarin Studio.
- Xamarin.forms: Introduced in Xamarin 3 on May 28, 2014 and allows one to use portable controls subsets that are mapped to native controls of Android, iOS and Windows Phone.
- On February 24, 2016: Microsoft announced it signed a definitive agreement to acquire Xamarin
- On March 30, 2016: Microsoft acquired the xamarin. And made it for all with free of cost.
32. What are disadvantage of Xaml in Xamarin.Forms?
- XAML cannot contain code. All event handlers must be defined in a code file.
- XAML cannot contain loops for repetitive processing. (However,ListView —can generate multiple children based on the objects in its ItemsSource collection.)
- XAML cannot contain conditional processing (However, a data-binding can reference a code-based binding converter that effectively allows some conditional processing.)
- XAML generally cannot instantiate classes that do not define a parameterless constructor. (However there is sometimes a way around this restriction.)
- XAML generally cannot call methods. (Again, this restriction can sometimes be overcome.)
33. When to use Xamarin.Forms vs Xamarin Native?
- Xamarin.Forms:
- Apps that require little platform-specific functionality.
- Apps where code sharing is more important than custom UI.
- Xamarin.IOS,Xamarin.Android:
- Apps that require specialized interactions.
- Apps with highly polished design.
- Apps that use many platform-specific APIs.
- Apps where custom UI is more important than code sharing.
34. What is is the difference between ListView & TableView?
- The ListView and TableView controls are so similar, you can think of them as a single control. The major difference between the two is the manner in which they lay out their items, and it’s easy to change the layout so each control emulates the other.
- The ListView control displays its data stacked vertically, much like a standard listbox. Use this control to display an ordered list of data, especially long lists that require scrolling like a list of email messages, a list of contacts, or search results.
- The TableView control displays its data stacked horizontally in rows (although you can alter this behavior and have it displayed in columns first, as well). You use this control when you need more space for rich visualization of each item to be displayed.
- One of the big differences is ListView provides you a ItemsSource and a Itemtemplate and TableView does not. So items must be added as children manually.
35. What are the layout controls available in Xamarin.Forms?
Layout is the process of sizing and positioning child elements in UI.
- ContentPresenter: A layout manager for templated views. Used within a ControlTemplate to mark where the content to be presented appears.
- ContentView: An element with a single content. ContentView has very little use of its own. Its purpose is to serve as a base class for user-defined compound views.
- Frame: An element containing a single child, with some framing options. Frame have a default Xamarin.Forms.Layout.Padding of 20.
- ScrollView: An element capable of scrolling if it’s Content requires.
- TemplatedView: An element that displays content with a control template, and the base class for ContentView.
- AbsoluteLayout: Positions child elements at absolute requested positions. User assigned anchors and bounds defines the position and size of the control.
- Grid: A layout containing views arranged in rows and columns.
- RelativeLayout: A Layout that uses Constraints to layout its children.
- StackLayout: A Layout that positions child elements in a single line which can be oriented vertically or horizontally. This layout will set the child bounds automatically during a layout cycle. User assigned bounds will be overwritten and thus should not be set on a child element by the user.