Arun's book review - Xamarin Cross-platform Application by Jonathan Peppers

Last week I started to read an interesting book Xamarin Cross-platform Application by Jonathan Peppers.

Jonathan Peppers is a Xamarin MVP and the lead developer.

Jonathan Peppers primarily covered Android (Xamarin.Android) and iOS (Xamarin.iOS) development in this book.

Who should read this book?

If you are a C# or windows phone developer with a desire to develop iOS and Android application and become a cross platform developer.

Prerequisite:

• You need a Mac computer (OS X 10.8)
• C# knowledge
• Of course motivation and desire to become a cross platform developer

What this book covers?

• Environment setup for cross platform development
• Basic concepts of each platform
• Process to submit your app to stores
• iOS and android development concepts
• Code sharing technique and unit test
• Xamarin component store and leverage native Java & Objective-C libraries
• XamChat an instant messenger, using Azure Mobile Services for data storage and cross platform push notifications.

Few things I like most that have been covered in this book are design pattern (MVVM, DI and IoC) used for mobile applications development with example and different code sharing techniques with advantage and disadvantage.

What this book won’t provide?

Windows phone development

Details of iOS and Android development

Visual studio integration

In short this book gives a quick start for any one who wants to learn about Xamarin and become a Xamarin developer.

What is Xamarin? - Part II

Checkout Part I

Is Xamarin the best cross-platform development tool?

Xamarin enables the best of both worlds—providing the advantages of native UI, access to device features, and native performance coupled with the time-to-market advantages of code sharing and reuse.

Companies that build software using Xamarin achieve cost effective cross platform development and have the flexibility to handle native user experience.

Why C# is Awesome?

• Setting up event handling is a breeze
• The async and await keywords make asynchronous programming incredibly pleasant and code will be much more linear and much easier to understand
• Use LINQ to query, filter and select data from in-memory arrays, or from databases such as SQLite
• Statically typed so you avoid a pitfall of errors that afflict other languages
• Conditional compilation
• Intellisense, lambdas, etc. are all awesome
• Json.NET offers simple conversions to and from JSON strings and .NET objects, with SerializeObject and DeserializeObject methods
• Parsing XML is easy

How Xamarin.Android works?

Android has its own runtime environment called Dalvik, which is used to execute conventional java based Android applications. Android’s platform specific functionality is made accessible through Java APIs that are tied to the Dalvik environment.

Xamarin.Android applications use the Mono and Dalvik runtimes at the same time, allowing developers to take advantage of the full range of functionality offered by both environments. Mono itself operates on Android much as it would in any other computing environment—it uses standard Mono JIT compilation. Fully transparent interaction between Mono and Dalvik is made possible by leveraging standard Java Native Interface (JNI) calls. Android’s open platform model enables Xamarin to leverage the full power of Mono while providing deep interoperability with the platform’s native development stack. As a result, Xamarin applications run just like regular Java-based Android applications, but with full access to all of the functionality provided by Mono.

The Managed Callable Wrapper is the wrapper code that converts Mono generated code to Java Code. MCW is called when managed code in Mono runtime needs to invoke Android code in Dalvik VM. 

The Android Callable Wrapper is invoked when the Android runtime wants to call the Managed Code after an Android event.

Xamarin Developer Certifications

Xamarin skills are increasingly in demand – certifications let the market know you represent top talent

How do I preserve application data/cache on device/emulator between deployments?

Preserve application data/cache on device/emulator between deployments

Xamarin Studio Users:

Xamarin Studio -> Preferences -> Projects -> Android

Check/ Uncheck  - Preserve data/cache between application deploys

Visual Studio Users:
Tools -> Options -> Xamarin
Check/Uncheck - Preserve application data/cache on device between deploys

*If Xamarin option is not available then click on Show all settings check box in Options window