This document discusses cross-platform mobile app development approaches. It describes building native apps for each platform separately, which has high costs. It also describes building apps with HTML/web technologies, which provides consistency but a subpar experience. The document recommends the Xamarin approach, which uses C# and shared code across platforms for better performance and experience than hybrid approaches. It outlines features of Xamarin Forms for building user interfaces once and deploying to multiple platforms.

1. MOBILE APP DEVELOPMENT WITH

2. Mohit Chhabra
Senior Software Engineer
Harman International
mohitchhabra@techie.com
@Mohit_techy

3. App delivery
lifecycle
Design & Develop
TestMonitor
100+ apps 1000+ devices

4. Cross platform != Hybrid

5. Xamarin != React Native,
Phonegap etc.

6. Customer pays for experience
not for technology
* Experience here relates to end user experience (UX: User Experience) offered to
the customer by your app/website

7. I have a question for you
What device do you use?

8. Cross-Platform Mobile Development
▪ Building High quality apps is hard
• Different presentation styles, interaction
styles and software stack
• Different screen sizes, input modes and
hardware capabilities
• New devices and OS versions are introduced
multiple times per year
• New consumer applications regularly
extend and revise the standards and
set the bar higher for good mobile
applications

9. Client Technology Choices

10. Silo: Build App Multiple Times
No shared code • Many languages & development environments • Multiple teams
Objective-C
in
Xcode
Java
in
Android
Studio
C#
in
Visual Studio

11. ▪ Full native experience
▪ Total access to the device as provided
by SDK
▪ Share Web API
▪ Minimal re-use mostly on back end
Web API
▪ Higher development cost from
multiple teams (silo teams) or
expensive multi-device developers
▪ Multiple codebases to maintain and
extend
▪ One platform rules the others are
subservient
Benefits Challenges
Silo: Build App Multiple Times

12. HTML: Write Once, Run Everywhere
App
Generator
Lua
Javascript
Actionscript
HTML+CSS
Limited native API access • Slow performance • Poor user experience

13. Target Browser Not OS
Web Site

14. ▪ Provide consist experience regardless
of target
▪ Cheap as it is just HTML
▪ Single codebase to maintain and
extend
▪ No need for revenue sharing as no
need to be in app stores
▪ User experience tends to be webish
and not native
▪ Need to still test and debug multiple
targets
▪ Features tend to be a subset common
to all targets
Benefits Challenges
HTML: Write App using Mobile Web

16. Xamarin Approach

17. Xamarin Forms Approach
Shared UI Code

18. Shared vs PCL (Portable Class Library)
▪ A Shared Project is not directly
compiled (.dll is not generated),
instead files are compiled into .dll of
project that references it
▪ Can write platform specific code in a
same file using compiler directives
#ifdef
▪ Cluttered implementation for large
projects
▪ Cannot be used other than Xamarin




• Shared • PCL (Portable Class Library)

19. Shared code implementation

20. Shared vs PCL (Portable Class Library)
▪ Shared code restricted into compiling directives is more difficult to read, slowing
down the development process.
▪ PCL code is much cleaner and maintainable but that is subjective to your
development practices (you may end up writing too much boiler plate code)
▪ If you are starting with Xamarin PCL is a better choice for better usability and
compatibility across other .NET platforms
Which suits better?

23. Xamarin + Xamarin.Forms Approach
▪ Quickly and easily build native user
interfaces using shared code
▪ Xamarin.Forms elements map to native
controls and behaviors
▪ Mix-and-match Xamarin.Forms with
native APIs
Shared UI Code

24. Native Performance
Xamarin.iOS does full Ahead Of
Time (AOT) compilation to
produce an ARM binary for
Apple’s App Store.
Xamarin.Android takes advantage of
Just In Time (JIT) compilation on the
Android device.

25. Anything you can do in Objective-C, Swift, or Java
can be done in C# and Visual Studio with Xamarin.

28. ✓ 40+ Pages, layouts, and controls
(Build from code behind or XAML)
✓ Two-way data binding
✓ Navigation
✓ Animation API
✓ Dependency Service
✓ Messaging Center
Shared C# Backend
Shared UI Code

29. Layouts
Pages
Stack Absolute Relative Grid ContentView ScrollView Frame
Content MasterDetail Navigation Tabbed Carousel

30. ActivityIndicator BoxView Button DatePicker Editor
Entry Image Label ListView Map
OpenGLView Picker ProgressBar SearchBar Slider
Stepper TableView TimePicker WebView EntryCell
ImageCell SwitchCell TextCell ViewCell

31. Xamarin.Forms Ecosystem

32. <?xml version="1.0" encoding="UTF-8"?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="MyApp.MainPage">
<TabbedPage.Children>
<ContentPage Title="Profile" Icon="Profile.png">
<StackLayout Spacing="20" Padding="20"
VerticalOptions="Center">
<Entry Placeholder="Username"
Text="{Binding Username}"/>
<Entry Placeholder="Password"
Text="{Binding Password}"
IsPassword="true"/>
<Button Text="Login" TextColor="White"
BackgroundColor="#77D065"
Command="{Binding LoginCommand}"/>
</StackLayout>
</ContentPage>
<ContentPage Title="Settings" Icon="Settings.png">
<!-- Settings -->
</ContentPage>
</TabbedPage.Children>
</TabbedPage>

36. macOS Preview
Enhanced GestureRecognizers
Android Support Libraries
PlatformSpecifics
Fast Scroll
NavigationPage Translucency
Blur Behind
Partial Collapse MasterPage
Native Control Binding
Map Extensibility
Fast Renderers Preview
Startup Time
ListView Scrolling
Memory Improvements
XAMLC
Bindable Picker
Frame Corners
Tizen
Forms Previewer
FlexLayout Preview
Xamarin.Forms Embedding
DataPages

37. Source: Matthew Robbins - MFractor

38. Get Started Today
xamarin.com

39. Useful resources
http://bit.do/xamuniyoutube
http://bit.do/getxamarinuniveristy
https://azure.microsoft.com
https://docs.microsoft.com

40. Introducing
Microsoft Azure

41. What is the cloud?

43. On Premises
Storage
Servers
Networking
O/S
Middleware
Virtualization
Data
Applications
Runtime
Youmanage
Infrastructure
(as a Service)
Storage
Servers
Networking
O/S
Middleware
Virtualization
Data
Applications
Runtime
ManagedbyMicrosoft
Youmanage
Platform
(as a Service)
ManagedbyMicrosoft
Youmanage
Storage
Servers
Networking
O/S
Middleware
Virtualization
Applications
Runtime
Data
Software
(as a Service)
ManagedbyMicrosoft
Storage
Servers
Networking
O/S
Middleware
Virtualization
Applications
Runtime
Data

44. Cloud Services hungry kya!
On Premises
Made at home
Toppings
Tomato Sauce
Cheese
Fire
Owen
Pizza Dough
Soda
Dining Table
Electricity/Gas
Youmanage
IaaS
Take and Bake
Topping
Tomato Sauce
Cheese
Fire
Owen
Pizza Dough
Soda
Dining Table
Electricity/Gas
ManagedbyVendor
Youmanage
PaaS
Pizza delivered
ManagedbyVendor
Youmanage
Topping
Tomato Sauce
Cheese
Fire
Owen
Pizza Dough
Dinning Table
Electricity/Gas
Soda
SaaS
Dine out
ManagedbyVendor
Topping
Tomato Sauce
Cheese
Fire
Owen
Pizza Dough
Dinning Table
Electricity/Gas
Soda

46. Why the
cloud?
• Rapidly setup environments to drive business
priorities
• Scale to meet peak demands
• Increase daily activities, efficiency and reduced cost.

47. Infrastructure
designed for Scale

48. Demo: Azure Portal

49. Azure App Service
Build and scale great cloud apps
Web Apps
Mobile Apps
Logic Apps
API Apps
.NET, Java, Node.js, PHP, Python
Auto patching
Auto scale
Integration with existing apps
Continuous deployment

51. RESTAPI
Offline
sync
Facebook Twitter Microsoft Google Azure Active
Directory
Azure Mobile Apps
WindowsAndroid
Chrome
iOS
OSX
In-AppKindle
Backend code
SQL MongoTables O365 API Apps
Offline Sync

53. Create a Mobile Service
MobileService = new MobileServiceClient(
"https://myapp.azurewebsites.net");

54. Create tables
IMobileServiceSyncTable<TodoItem> syncTable;
public async Task Init()
{
const string path = "syncstore.db";
var db = new MobileServiceSQLiteStore(path);
db.DefineTable<TodoItem>();
}
await MobileService.SyncContext.InitializeAsync(db);
syncTable = MobileService.GetSyncTable<TodoItem>();

55. Push and pull with sync table
private async Task SyncAsync()
{
await MobileService.SyncContext.PushAsync();
var query = syncTable.CreateQuery();
await syncTable.PullAsync("todoItems", query);
}
private async Task InsertTodoItem(TodoItem todoItem)
{
await syncTable.InsertAsync(todoItem);
await MobileService.SyncContext.PushAsync();
}

56. Query local table
public async Task<IEnumerable<TodoItem>> GetOpenItemsAsync()
{
return await todoTable
.Where(item => item.Complete == false)
.ToEnumerableAsync();
}

59. Notification Hub
• Maps between tags and handles
1. Get PNS handle
4. Send to device
2. Store PNS handle 3b. Request notification
Use device handles
3a. Request notification
Use logical users/tags
5. Manage device handles

61. Shopping Demo App
Azure Services:
• Cognitive Services (Emotion API)
• Storage
• On/offline sync
• Push notifications
• Authentication
What’s Available:
• Complete sample app with documentation
• Individual “quick starts”
github.com/Microsoft/XamarinAzure_ShoppingDemoApp

62. Shared C# codebase • 100% native API access • High performance
iOS C# UI Windows C# UIAndroid C# UI
Shared C# Mobile C# Server
Linux/Mono
CoreCLRAzure
Shared C# Client/Server

66. Get started today at
http://azure.microsoft.com

69. https://appcenter.ms/signup

71. Our pipeline
Code CI Test Deploy Monitor
We are so agile

72. Code CI Test Deploy Monitor
Our pipeline
And slow

73. Code CI Test Deploy Monitor
Our pipeline
And slow

74. Code CI Test Deploy Monitor
Our pipeline
Let’s speed it up

76. Monthly Active Users

77. Failure to learn, failure to succeed

78. Monthly Active Users
Us
The competition

79. How do you solve this problem?

83. Live Update
Storage
Push Notifications
Crash Reporting
Identity
Tables

84. Live Update Storage
Push Notifications
Crash Reporting IdentityTables
Visual Studio Mobile Center
Mission control for mobile apps

85. Delivering continuously means
learning continuously

87. Visual Studio App Center
Automate your entire mobile app
lifecycle in a few easy steps
Deliver high-quality apps that keep
users coming back for more
Move faster and increase quality with
the tools you already use—we
support a wide variety of platforms

88. Get started today!