Best Xamarin Training Institute

1. Xamarin Interview Questions And Answers

2. 1)What is Xamarin? Xamarin is cross platform mobile technology. Using C#.net we can implement platform specific (IOS, Android, Windows Phone) mobile applications or cross platform mobile applications. 2) What is the difference between Native App and Cross Platform APP? Native App: If we want to develop native apps, we need to choose the specific native language (C#, Objective-C, Swift, and Java) for developing specific native app for Windows, Android, iOS. Cross Platform App: This is the way to develop all three mobile apps using single code base wrapped in a native application layer, but it always requires customization of interfaces to native languages. 3) What are the programming languages that support Xamarin Development? Xamarin is unique in this space by offering a single language – C#, class library, and runtime that works across all three mobile platforms of iOS, Android, and Windows Phone (Windows Phone’s native language is already C#) Also offers xaml support for creating user interface.

3. 4)How many ways we can create Xamarin applications? There are two ways to deliver native iOS, Android, and Windows apps using Xamarin Technology Traditional Xamarin approach: This approach can provide direct access to platform-specific API’s. And we can create platform specific apps such as using Xamarin.iOS for iOS applications, using Xamarin.Android we can create Android applications. Xamarin.forms: This architecture is the same as that of traditional cross-platform apps. The most used method is to implement Portable Libraries or Shared Projects to save the shared code, and then create specific applications for each platform that will consume this shared code.  5) What are the different code sharing techniques in xamarin.forms? There are two alternative methods for sharing code between cross-platform applications: • Portable Libraries(PCL) • Shared Projects The goal of a code-sharing strategy is to support the architecture, where a single codebase can be utilized by multiple platforms.

4. 6)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.

5. 7)What is the difference between Modal pages and Modeless pages? Modal Page: We’ll use modal pages when your application needs some information from the user and you don’t want the user to return to the previous page until that information is provided. Below C# code is used to navigate to specific page name is DetailPage.  async void ModelPageNavigation ()   {       await Navigation.PushModalAsync (new DetailPage ()); //Navigate to Details Page   }   Modeless Page: The difference between modal and modeless pages mostly involves the user interface that the operating system provides Back button on the page to return back to the previous page. async void ModelessPageNavigation ()   {      await Navigation.PushAsync (new DetailPage ()); //Navigate to Details Page, will create Back button navigation page   }  

6. 8)What is the other name of Xamarin 2.0? Xamarin 2.0 wat the second release of Xamarin which released in February 2013 and is also known 9)What is the basic architecture of Xamarin.Forms project? Xamarin.Forms can consists of four (this varies based on requirements) projects under one solution. .NET Standard, PCL or Shared Project iOS Project Android Project UWP Project 10)What are the different kinds of Pages in Xamarin.Forms? Fortunately Xamarin.Forms support multiple page representations, And every representation is having its own purpose like below:

7. ContentPage: A Page that displays a single View, often a container such as a StackLayout or a ScrollView. MasterDetailPage: A Page that manages two panes of information. NavigationPage: A Page that manages the navigation and user-experience of a stack of other pages. TabbedPage: A Page that allows navigation between children pages, using tabs. TemplatedPage: A Page that displays full-screen content with a control template, and the base class for ContentPage. CarouselPage: A Page allowing swipe gestures between subpages, like a gallery. 11) Name 5 Apps That Were Designed With Xamarin For Ios? • Apocalypse Archer: Zombie Invasion • Stone Skimmer - The skimming action game • QuickPlan - Project Plan HD • KorfballScout • Newspager.

8. 12)What are the different code sharing techniques in xamarin.forms? There are two alternative methods for sharing code between cross-platform applications: • Portable Libraries(PCL) • Shared Projects The goal of a code-sharing strategy is to support the architecture, where a single codebase can be utilized by multiple platforms. 13)What is Data Binding in Xamarin? Data binding is a technique to automatically synchronize a user interface with its data source. When a binding is established and the data or your business model changes, then it reflects the updates automatically to the UI elements and vice versa.  Data binding connects two objects, called the source and the target. The source object provides the data. The target object, which must be a bindable property, will consume (and often display) data from the source object. It is also possible to bind, not to a standard data source, but to another element on the page

9. 14) What are different type of Data Binding modes in Xamarin? Data binding connects two objects, called the source and the target. So the relationship between target and source is defined by members of the BindingMode enumeration and there is four kinds of binding modes are available in Xamarin.Forms. Default (Optional & not considered) OneWay — changes in the source affect the target (normal). OneWayToSource — changes in the target affect the source. TwoWay — changes in the source and target affect each other. 15)What are uses of DataPages in Xamarin.Forms? Data pages allow developers to quickly and easily consume a supported data source and render it using built-in UI scaffolding that can be customized with themes.

10. 16)How many ways can we share the code? There are three ways we can share code: Shared Project: Here, if required, we write platform specific code using #if compiler directives. Portable Class Libraries: Here, we create a PCL targeting the platforms we wish to support and then we use Interfaces & Dependency Services to use platform specific functionality. .NET Standard Libraries: It works similar to the PCL and requires Interfaces to work with platform specific functionality. 17)What are Triggers? How many types of Triggers are available? Triggers allow us to declare actions in XAML which changes the appearance of the control when specific condition is met for specific control property or specific event is raised. We can add triggers to the control-level, page-level or application-level in the resource dictionary. There are four types of Triggers. Property Trigger: executed when a property on a control is set to a particular value Data Trigger: It is similar to the property trigger but it leverages the use of data binding Event Trigger: occurs when some specified event is raised on the control Multi Trigger: allows multiple trigger conditions to be set before an action occurs

11. 18)Why Xaml in Xamarin.Forms? XAML(Extensible Application Markup Language) allows developers to define user interfaces in Xamarin.Forms applications using markup rather than code. XAML defines the visual appearance of a UI, and an associated code-behind file defines the logic. The UI design can be adjusted without necessarily making changes to the logic in code-behind. XAML in this role simplifies the workflow between individuals who might have a primary visual design responsibility and individuals who are responsible for app logic and information design. 19)What is ResourceDictionary? • ResourceDictionary is used to define the XAML Resources which can be re-used more than once throughout the Xamarin.Forms application. • XAML resources are the definition of objects which can be used more than once. • ResourceDictionary allows all such resource objects declared at one place. • Generally, we can define Styles, ControlTemplates, DataTemplates, Colors and Converters into the ResourceDictionary. • In XAML, these resources can be accessed using the StaticResourceMarkup Extension. • ResourceDictionary can be declared at either Element Level (inside specific Element), Page Level (inside Page) or Application Level (inside App.xaml).

12. 20)What is difference between Margin & Padding property? Margin is applied to the outside of you element hence effecting how far your element is away from other elements. Padding is applied to the inside of your element hence effecting how far your element's content is away from the border. 21)What are different type of Data Binding modes in Xamarin? Data binding connects two objects, called the source and the target. So the relationship between target and source is defined by members of the BindingMode enumeration and there is four kinds of binding modes are available in Xamarin.Forms. Default (Optional & not considered) OneWay — changes in the source affect the target (normal). OneWayToSource — changes in the target affect the source. TwoWay — changes in the source and target affect each other.

13. 22)What is Xamarin.Android? Xamarin.Android allows us to create native Android applications using the same UI controls we would in Java,except with the flexibility and elegance of a modern language(C#),the power of the .NET Base Class Library(BCL). 23)Can we develop Windows mobile application using xamarin Studio in mac OS? No.We need Windows machine for develop windows based application. 24)What is use of MOBILE conditional compilation? Xamarin projects always define MOBILE Which is true for both iOS and Android application projects #if_MOBILE_ //XamariniOS or Android specific code #endif

14. 25)What is the difference between Xaml & axml in Xamarin Technology? • AXML and XAML are two different XML specifications. • AXML is just supported/available for Xamarin.Android. • XAML is the way Xamarin Forms could standardize Cross Platform UI based on XML specification. • XAML is the way Xamarin Forms could standardize Cross Platform UI based on XML specification. • If you are using native Xamarin Android you will do UI using axml, if using Forms then using XAML.

15. XamarinTraining – GREENSTECHNOLOGYS Xamarin is a cross-platform development tool. It solves dilemmas many developers face when developing cross-platform apps: separate coding languages and UI paradigms. With Xamarin, you can use C# for iOS, Android, and Universal Windows apps. And with Xamarin Forms, interface design for all three platforms can be accomplished within its XAML-based framework. http://www.greenstechnologys.com/xamarin-training-in-chennai.html Address - No.11, First Street, PadmanabhaNagar, Adyar Contact - 8939915577