Xamarin Interview Questions and Answers
Founded in the year 2011 in the month of May, Xamarin is a cross-platform development company owned by Microsoft. It is a San Francisco based company that has created Mono, Xamarin.android and Xamarin.iOS in recent years. Xamarin has cross platforms that implement Common Language Infrastructure as well as Common Language Specifications. Codes can be shared on multiple platforms such as Windows and many more. With its growing popularity, there has been an increase in the level of Xamarin Interview questions. Xamarin has a C# shared codebase which makes it easier for the developers to write native Windows, Android and iOS applications with shared codes and native user-interfaces.
Advantages of Xamarin
- 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.
Most Frequently Asked Xamarin Interview Questions
| Xamarin Forms | Xamarin Native |
|---|---|
| In Xamarin.Form you share both the business logic and the UI and allows its users to share its UI coding to multiple platforms. | Xamarin Native allows its users to develop a platform-specific user application. |
| Cross-platform applications are less efficient in performance. | Cross-platform applications are more efficient in performance. |
| The application size is larger. | The application size is smaller |
| Easier to maintain and scale because 80-95% of code is common between platforms where the deployment of an application takes place. | Moderate scaling and maintenance. |
| To develop a mobile application a limited timeframe and budget are needed. | Requires more time than Xamarin Forms to develop a mobile application. |
Native App: Specific native language(C#, Objective C, Swift, Java) is needed to develop a specific native app for Windows, Android or IOS. These are all needed if we are looking forward to developing a native app
Cross-platform App: Using a cross-platform, a developer can develop an app for all three mobile platforms. It uses a single code base wrapping in a native application layer. Customization of interfaces to native languages is always required.
Xamarin is basically a cross-platform technology that uses a single codebase with C# where the user can build suitable native user interfaces as well as native applications for platforms such as Windows, macOS, etc. It is a one-stop platform whose tools can be used in any of the operating systems and thus various applications can be developed which can run on these platforms without any kind of significant change in the code.
Xamarin is very unique as it uses only one language, and that language is C#, it has a class library and runtime that work throughout all the three platforms of iOS, Android and Windows phone( The native language of Xamarian is already C#). It also offers Xami support for creating a user interface.
There are several disadvantages of Xaml in Xamarin. Forms which can be explained by the following points
- XAML is incapable of containing the code. Usually, the code file must contain all the event handlers.
- XAML does not have the feature of loops for repetitive processing. There are some tools such as ListView, that can generate various children and do further processing.
- Conditional processing cannot be contained by XAML. However, the data binding feature eventually allows some of the conditional processing.
- Classes that do not define parameterless constructor, cannot be instantiated by XAML.
- Generally, methods cannot be called XAML.
- Windows Phone, Windows and UWP cannot be created with the help of Xamarin studio but it can be created through Visual studio.
- In the Mac operating system, it is possible to develop Android and iOS apps with the help of Xamarin studios whereas this is not possible while using Visual studio.
- The feature of Xamarin studios to develop Android apps only in Windows helps the user to switch to visual studios for application development.
- To develop apps in Xamarin. Form, the user requires Windows 10 and Visual Studio version 2015.
Using Xamarin Technology, there are two ways in which we can deliver native iOS, Android or Windows apps:
- Traditional Xamarin approach: Through this, direct access to platform-specific API can be provided. Platform-specific apps can also be created using Xamarin, for example, iOS-specific for iOS applications. Android-specific apps can be created.
- Xamarin.Forms: It follows the same architecture as that of Traditional cross-platform apps. Implementation of portable libraries or shared projects to save the shared code and then creating specific applications for every platform that will use this shared code. These were the most used methods for implementation.
Xamarin uses a fully functional implementation of the .NET runtime known as Mono, which compiles the app into a native ARM which helps to execute the code using all the functionalities of C#. It uses all the features of C# and .NET such as memory management, .NET base class libraries, and reflection. Developers then use any of the features of the provided programming languages to create native APIs on iOS while taking care of Apple’s privacy policies.
| List View | Table View |
|---|---|
| List View shows its data stacked vertically | Table View shows its data horizontally |
| List View provides you item templates and item source | The table view doesn't provide any of these |
| Every cell in a ListView have the same type | You can mix different types of cells in Table View |
It has gained huge popularity since its release. As of 2017, Xamarin has been observed to be used by over 1.4 million developers across 120 countries in the world. Developers wish to enter this firm for a handsome package and a huge scope of work at the same time. With proper preparation, command in coding, confidence, and presence of mind, one can bag a respectable post in this firm.