This document provides an overview of developing cross-platform business apps using Visual Studio with Xamarin and Azure. It discusses where to start development, including considerations for targeting platforms and hosting. It then covers using Xamarin for cross-platform development across iOS, Android and Windows platforms. It demonstrates how to share code using shared asset projects or portable class libraries. The document also discusses programming skills needed like asynchronous programming and connecting to SharePoint. It shows how to set up the development environment in Visual Studio. Finally, it demonstrates how to integrate with Azure services for features like cloud data storage, push notifications and authentication.

1. Develop Business Apps
Cross-platform development using Visual Studio
with Xamarin and Azure
Alexander Meijers| SharePoint Lead Architect
Tuesday, April 14th 2015

2. Agenda
• Where to start?
• Development
• Cross platform
• Programming skills
• Development environment
• Windows Azure
• Known issues
• Takeaways & Roundup
• Resources

3. Where to start?
• Considerations
• Type of Business Apps

4. Considerations
• Targeting
• Single platform
• Cross platform
• Deployment
• Development versus production
• Release management
• Hosting of the App
• App Store or not to Store
• Other
• Localization
• Design
• Interaction
• Security
• Data storage
• Local storage in App
• Storage in the cloud
• Hybrid scenarios
• Data availability
• Scalability
• Data only available to App
• Data available to multiple solutions
• Data available cross Apps / Solutions
• Data transition
• Transforming data to another format
• Move data to specific location

5. Ask yourself the following questions
• Which platforms do i want to support?
• Which systems does my app connect to?
• How many (active) users do i expect?
• Do i need to read and write data from a data container?
• What is the data connectivity for my users?
• Are other systems doing something with my data?

6. Type of Business Apps
• Office Platform
• Office Apps
• SharePoint hosted Apps, Provider-hosted Apps
• Cloud
• Office 365 Apps
• Azure Apps
• Windows
• Universal Apps
• Windows Phone Apps
• Other platforms
• Android Apps
• iOS Apps

7. Development
Cross-platform
• Xamarin Platform
• Xamarin.Forms
• Development
• .NET Libraries
• Models

8. Xamarin Platform
• A platform which allows you to share code accross all platforms with
a single shared c# codebase
• Use the same language, APIs and data structures on every platform
• Platforms
• iOS, Android, Windows Phone, Windows, Mac
• Xamarin Apps
• Standard native user interface controls
• Compiled for native performance
• Leverage hardware acceleration

9. Xamarin tools
• Xamarin platform
• Xamarin Studio
• iPhone and Android App development on Mac
• Android App development on Windows PC
• Visual Studio with Xamarin libraries
• Windows Phone App development
• Android App development
• Mac and iPhone development only possible in combination with a Mac
running XCode and Xamarin Studio, connected by network with the
Windows PC

10. Devices & Emulators
• On screen emulators
• Real Phone (connection via USB cable)
Advantages Disavantages
Device • Easier to test
complex touch
interaction
• Feel for startup
and response
time
• Unlocking your Windows Phone
• Need of a developer account
• Android needs to have
debugging enabled
Emulator • Easier to test for
a variety of sizes
and forms
• Android emulators are very
slow
• Mac desktops don’t have touch.
Therefore difficult with controls

11. Xamarin development
Development Tools Language Platform
iOS XCode Objective-C Mac
Android Eclipse Java Lots of platforms
Windows Phone Visual Studio C# Windows PC
• Each language incorporates same sort methods or properties
• Example toggle between to states
• iPhone its a view called UISwitch
• Android its a widget called Switch
• Windows Phone its a control called ToggleSwitchButton
• All languages are object-oriented descendants of C

12. Xamarin Platform .NET Libraries
Platform .NET Library Name
iOS Xamarin.iOS MonoTouch
Mac Xamarin.Mac MonoMac
Android Xamarin.Android Mono for Android
These libraries are known as the Xamarin Platform. They contain
native Mac, iOS and Android APIs.

13. Shared code
• The trick is the ability of sharing code among the applications
• Platform independent code is isolated by moving it to a separate project
• The project is shared and referenced accross the other platform dependent
projects
• MVVM used in Xamarin projects
• Model (underlaying data), View (user interface, visuals and input), ViewModel (manage
data between Model and View)

14. Shared code – can be complicated
• Different platforms use a different
subset of the .NET Base Class
Library (BCL)
• Different platforms are built to a
different .NET Core Library Profile
• When creating cross-platform
solutions, each platform can only
use class libraries that are targeted
to the same profile within that
solution

15. Shared code - Strategy
Approaches Overview
Shared Asset
Project (SAP)
• Organize your source
code
• Use #if compiler
directives to manage
platform specific
requirements
Portable
Class Library
(PCL)
• Class library targeting
the platforms you
want to support
• Use interfaces to
provide platform
specific functionality

16. Shared code - Shared Asset Project
• Benefits
• Simplest approach
• The common code lives in the Shared Asset Project
• All platform projects are sharing the same code
• Branching possible to use compiler redirectives
• Application projects can include platform specific
references that the shared code can utilize
• Disavantages
• No output assembly
• During compilation the files are treated as part of
the referencing project. Code is not shared after
compilation
• Refactorings inside code in “inactive” compiler
directives will not update the code
• Code is not intendend for distributing to other
developers

17. Shared code - Portable Class Library
• Benefits
• Allows you to share code across multiple
projects
• Refactoring always update all effected
references
• The output of the shared code is a class library
• Allows you to share your code with other
developers
• Disavantages
• More difficult to implement. You need to
considerate the options
• You can’t use compiler directives
• Only a subset of the .NET framework is
available to use, determined by the profile
selected

18. Xamarin App development model
iPhone App
Xamarin.iOS
iPhone API
Android App
Xamarin.Android
Android API
Windows Phone App
Windows Phone API
Shared Asset Project or Portable Class Library
Solution with
C# projects

19. Xamarin.Forms - Apps
• Xamarin.Forms
• Introduced on may 28th, 2014
• Write user-interface code for all platforms at once
• Xamarin.Forms application
• 3 platform projects
• 1 shared code project
• The shared code project contains most of the application
• The platform projects contains mostly stubs
• Xamarin.Forms Framework
• Xamarin.Forms.Core
• Xamarin.Forms.Xaml
• Xamarin.Forms is based on MVVM

20. Xamarin.Forms - App development model
iPhone App
Xamarin.iOS
iPhone API
Android App
Xamarin.Android
Android API
Windows Phone App
Windows Phone API
Shared Asset Project or Portable Class Library
Solution with
C# projects
Xamarin.Forms.Core / Xamarin.Forms.Xaml

21. Xamarin.Forms - Example
• Example displays a switch
on all three platforms with
a single XAML file

22. Xamarin APIs
• http://api.xamarin.com
• You will find here:
• Base Class Library
• MonoMac Framework
• Xamarin.Android Framework
• Xamarin.iOS Framework
• Xamarin.Forms
• Other APIs found here from
other Xamarin products

23. DEMO
FormsGallery

24. Demo – Run the project

25. Programming
skills
• Asynchronous programming
• Retrieve data from SharePoint
• Model – View - ViewModel

26. Programming skills – asynchronous
• Working with mobile applications that interact with network, database,
files and device hardware reading are much more slower than in normal
conditions due to communication bottlenecks
• Asynchronous allows us to run delayed tasks in the background
• The program itself can continue without holding up by some task
• Available with .NET Framework 4.5 or higher
• A new simplified approach for running asynchronous tasks
• .NET APIs contain classes supporting asynchronous methods and
properties to improve responsiveness
• The task has a state (Running, Finished or Cancelled), a result and is able
to throw exceptions

27. Programming skills – asynchronous
• Keywords
• async  let the compiler know that
the method needs to be handled
separately
• await  Let the compiler know the
suspension of the relative running
async task
• Return types
• Task or Task<TResult>
• Task is used when the method has no
return statement of does not return an
operand

28. What happens?
1. Function is called
2. Calls an async method on the
object
3. Something causes a delay. It
yields control to its caller.
4. The method continues because
its not awaited
5. The method is executed
synchronous
6. No work further. It now awaits
on the result of the
asynchronous call
7. The method completes and
returns the result.
8. It calculates the length and
returns it

29. Retrieve data from SharePoint
• Use WebClient with authentication
credentials using
SharePointOnlineCredentials()
• JSON as result
• Example: Jtoken listItems = GetList(new Uri(https://appztekonline-
public.sharepoint.com”), Credentials(), “B
• If called from an Azure Service you will need to configure some additional
settings
• Allowed Origins
• Other

30. Model – View - ViewModel
• A model which allows you to create shared code projects at ease
• Model (business logic and underlaying data)
• View (presentation, user interface, visuals and input)
• ViewModel (presentation logic, manage data between Model and View)

31. Development
environment
• Software installation
• Development setup
• Android specific
• Android API levels
• Android Virtual Device

32. Dev environment – Software installation
• Windows 8 or higher
• Hyper-V enabled
• Needed for emulators (Windows Phone, Android)
• Visual Studio 2013 with Update 4
• Contains the Windows Phone SDK
• Xamarin for Windows
• Xamarin Android Player for Windows
• Only when you want to develop for Android!!
• You will need VirtualBox (not possible with Hyper-V enabled)
• Update the Android SDK Manager

33. Dev environment – Development setup
• Create a blank Xamarin App based on Xamarin.Forms Shared
• Remove the iOS project
• Mac platform needed and not present (in this case)
• Use Android Virtual Device Manager
• Create or use device definitions
• Create Android virtual devices based on device definitions
• Project properties of the Android project
• Define compile level
• Define minimum target level
• Define Android version

34. Dev environment - Android API Levels
• API Level determines for which Android versions you can deploy
• Choose the API Level
• Install the SDK platform for that level
• Install the system images for that level
• Sources and samples of SDK are available

35. Dev environment - Android Virtual Device
• Create Android Virtual Device
• Choose Device
• Choose target (API Level need
to be installed)
• CPU/ABI
• In some cases you need to
restart Visual Studio to get the
device listed under the start
button

36. DEMO
Configuration

37. Demo - Configuration

38. Windows Azure
• Why Azure?
• Xamarin and Azure
• Azure Mobile Services
• Azure Messaging component
• Azure Active Directory authentication

39. Why Azure?
• Set of great tools completely integrated with Xamarin
• Azure Mobile Service
• Push notifications
• All the benefits of a great platform
• Scalability
• Uniform platform and layer in your solution
• Data synchronization
• Asynchronous
• Offline data synchronization
• Authentication with Active Directory

40. Xamarin and Azure
• Microsoft Azure plugs easily into Xamarin projects
• Incorporates Azure features like;
• Cloud data storage
• Cross-platform push notifications
• Xamarin has components available to integratie it!
• Azure Messaging component

41. Azure Mobile Services
• Add structured storage,
authentication, push
notifications and more to
your Xamarin based mobile
application using Microsoft
Azure Mobile Services.
• https://components.xamarin
.com/view/azure-mobile-
services/

42. Azure Messaging component
• Send push notifications to your iOS, Android
and Windows apps
• Allows you to register with Azure Notification
Hubs
• Send notifications from any backend
• Target content to specific user segments
• Use templates to tailor notifications
• Due to the notification hubs you can scale op
to millions of devices and billions of push
notifications
• http://components.xamarin.com/view/azure-
messaging

43. Azure Active Directory Authentication
• Use Active Directory to authenticate users in Xamarin mobile
applications
• Use the same organizational account that employees use to sign in
to their corporate environment
• Secure resources like;
• Files, links, Web APIs, Office 365 and more

44. Azure Active Directory Authentication
• Get it up and running in three steps
• Register with Azure Active Directory
• https://www.windowsazure.com
• Configure Service Access for Mobile
Application
• http://developer.xamarin.com/guides/cross-
platform/azure/active-directory/
• Develop mobile apps using the service access
• Examples of services you can access
include:
• Graph API, Web API and Office 365

45. DEMO
Todo list with data in Azure

46. Demo – Create mobile service

47. Demo – Get project

48. Demo – Run the project

49. Known issues
• Fastdev directory creation failed

50. Known issues
Issue  FastDev directory creation failed
Resolutions  Turn off Fast Deployment in project properties

51. Takeaways &
Roundup

52. Takeways & Roundup
• The Xamarin platform is great for developing cross-platform
business apps
• Understand the technology of Shared Code, choose wisely!
• Not everything is cross-platform. Specific functionality demands
written code per platform
• Get to know asynchronous programming with async and await
• The Azure platform is great for expanding your app with storage,
push notifications and security
• Integration between Xamarin and Azure

53. Resources

54. Sources & Resources
• Free e-book “Creating Mobile Apps with Xamarin.Forms” by Charles Petzold
http://blogs.msdn.com/b/microsoft_press/archive/2014/10/06/free-ebook-creating-mobile-
apps-with-xamarin-forms-preview-edition.aspx
• Xamarin platform
http://xamarin.com/platform
• Xamarin + Azure
http://developer.xamarin.com/guides/cross-platform/windows/microsoft-azure/
• Xamarin API documentation
http://api.xamarin.com/
• Xamarin FormsGallery demo – Great impression of the Xamarin.Forms
http://developer.xamarin.com/samples/xamarin-forms/FormsGallery/
• Xamarin early preview setup – Windows Phone 8.1 development
http://developer.xamarin.com/guides/cross-platform/xamarin-forms/windows/installation/
• Managing your Azure environment
https://manage.azure.com

55. Questions?