At Build 2014 the world was introduced to the idea of creating Universal Windows apps. This technology will allow developers to extend platform commonality across multiple Windows devices from one shared project. In this session I will demonstrate what you will need to know to get going quickly on building one application for both Windows Phone 8.1 and Windows 8.1 OS. We will also see how to extend your project to include other new features. This talk was given at ConFoo 2015.

1. An Introduction to
Universal Windows Apps
Ken Cenerelli
@KenCenerelli

2. What is it?
 Build one app that targets Windows and Windows Phone
 Provides a common experience, shared app identity, single app
purchase, shared in-app purchases and shared data/profile
 It is not:
 A single binary
 A non-Windows application (i.e. Supporting Android & iOS)
 A non-native HTML/JavaScript application (i.e. Apache Cordova)

3. Overview
 Announced in April 2014
 Develop once for all Windows devices using a unified
Windows runtime and set of tools
 Project structure comes from Linked Files, a technology since
the early days of .NET 2005

4. Platform Convergence
 Windows Phone 8.1, Windows 8 RT and Window 8.1 flavours of
Windows share a common runtime
 Existing Windows 8 apps can be migrated to shared projects
 Share code while just making tweaks to the UI
 Silverlight Phone 8.0 apps work on 8.1 without upgrade
The Windows Runtime API & Microsoft SDKs are
around 90% converged and closing

5. Why should you care?
 Windows 10 is coming with a free upgrade for Windows 8 so
exponentially more adoption within the enterprise
Source: OS Platform Statistics, http://www.w3schools.com/browsers/browsers_os.asp
 Flip side though is Windows Phone market share is 2.9%
compared to ~84% for Android and ~12% for iOS
Source: Smartphone OS Market Share, Q3 2014, http://www.idc.com/prodserv/smartphone-os-market-share.jsp

6. Things to know
 Multiple languages supported (C# or C++ with XAML,
C++ with DirectX, and JavaScript with HTML/CSS)
 The IDE is free
 Must be Visual Studio 2013 with Update 2 or later
 Works with the Express versions and the new Community Edition
 Physical device nice to have but not essential
 Requires a developer license for your computer
 Needs a Microsoft account (i.e. Windows Live account)
 Requires a developer account to publish ($20 CAD)

7. Demo
 Our first Universal Windows App

8. How to share code?
 Before UA there were:
 Linked Files
 Portable Class Libraries
 We now have:
 Shared Projects (Conditional Compilation)
 Partial Classes (Split the code across multiple files)
 Portable Class Libraries
 Base Classes
 User Controls
 Visibility

9. Things to share
 Reusable business logic (C# code)
 Resources & Assets (images)
 Views similar to both projects:
 Login Page
 Privacy Page

10. Demo
 Sharing code and views:
 Shared Projects
 Conditional Compilation
 Partial Classes
 XAML UI code

11. Rules of Thumb
 Conditional Compilation
 Can make code difficult to read
 Solves small, quick-hit platform problems
 Only supported when using the Shared project
 Partial classes
 Makes it easy to isolate platform code
 Difficult to see the entirety of your code
 Don’t expect to save time writing XAML
 Do expect to save time writing implementation code

12. Tips for design
 Think through the design for both platforms before you
start coding
 If you keep the Microsoft design, it means that the user
knows how to move around the app intuitively
 Device variability: Default for tablet Is landscape and
default for phone is portrait
 It’s okay if each version doesn’t look the same and
doesn’t have the same features
 There is no silver bullet solution
 There are just small choices you will make as you develop a
pattern of practice

13. Tips for development
 Develop apps in sync to solve problems in parallel
 Target lowest supported device for phone development
 ~50% of Windows Phone users use a low-end device
 Startup both projects in the emulator at the same time
 Use the Navigation Bar to segment your code per project
 Optimize the user experience for the device they are on

14. Testing
 Unit Tests
 Create separate unit test projects for each platform
 Coded UI
 Need Visual Studio Premium and Ultimate
 Windows App Certification Kit (WACK)
 Available as separate download
 Windows Store app test cases

15. Publishing
 Reserve a name in the store for your app
 Valid for 12 months
 Must match the Display Name in your app manifest
 If the app connects to internet, must have a Privacy Policy
 Publish first app and then associate the second to it
 Approval takes anywhere from 0.5 days to a week

16. Resources
 Get started with Universal Windows Apps:
 http://bit.ly/1L45n62
 http://bit.ly/1MrKx3Q
 http://bit.ly/1u033XM

17. Summary
 Please fill out your surveys!
 Title: An Introduction to Universal Windows Apps
 https://joind.in/talk/view/13288
 Contact Details:
 @KenCenerelli
 Ken_Cenerelli@Outlook.com
 kencenerelli.wordpress.com/contact