AnDevCon - Android and iOS Apps in C# with Xamarin

2. James
Montemagno
Principal Program Manager – Mobile Developer Tools, Microsoft
motz@microsoft.com motzcod.es @JamesMontemagno
Weekly development podcast
mergeconflict.fm

3. Xamarin Platform is included
for free in Visual Studio
Including Community Edition

4. Open Source – open.xamarin.com

5. What is native?

6. ? ? ?

7. Architecting mobile apps

8. Silo approach
iOS WindowsAndroid
Objective-C
Xcode
C#
Visual Studio
Java
Android Studio
No shared code • Many languages and development environments • Multiple teams

9. Write once, run anywhere
Lua
Javascript
Actionscript
HTML+CSS
Limited native API access • Slow performance • Poor user experience
App
generator

10. iOS C# UI Windows C# UIAndroid C# UI
Shared C# logic
Xamarin’s unique approach
Shared C# codebase • 100% native API access • High performance

11. Windows APIs
Microsoft.Phone Microsoft.Networking Windows.Storage Windows.Foundation Microsoft.Devices
System.Data System.Windows System.Numerics System.Core System.ServiceModel
System.Net System System.IO System.Linq System.Xml
C#

12. Android – 100% API coverage
Text-to-speech ActionBar Printing Framework Renderscript NFC
System.Data System.Windows System.Numerics System.Core System.ServiceModel
System.Net System System.IO System.Linq System.Xml
C#

13. iOS – 100% API coverage
MapKit UIKit iBeacon CoreGraphics CoreMotion
System.Data System.Windows System.Numerics System.Core System.ServiceModel
System.Net System System.IO System.Linq System.Xml
C#

14. Building User Interfaces

15. Xamarin Native
3 Native User Interfaces
Shared App Logic
iOS C# Windows C#Android C#
Shared C# Logic

16. Xamarin.Forms
Shared Native User Interface
Shared App Logic
Shared C# Logic
Shared UI Code

17. 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.
ARM
BINARY
Runs
natively
.APPAOT
.NET
C#
Bindings
.APKCompile
and Link
.NET
C#
Bindings
IL
+
JIT
Runs
natively

18. Magical Android Bits

19. ARM BINARY
Runs natively
.APKAOT
.NET
C#
Bindings

21. ✓ Always up-to-date
Same-day support:
• iOS 5
• iOS 6
• iOS 7
• iOS 8
• iOS 9
• iOS 10
Full support for:
• Apple Watch
• Apple TV
• Android Wear
• Amazon Fire TV
• Google Glass
• and much more

22. Visual Studio Visual Studio for Mac

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

24. •LINQ Support
•Work With XML Easily XDocument
•Event Handling & Delegates
C# is Pretty Awesome

25. Beautiful & Maintainable Code
Async/Await is Awesome

26. Using Awareness API

27. Using Awareness API

28. App building time

29. Sharing Code

30. .NET Standard Libraries
.NET STANDARD LIBRARY
One library to rule them all

31. NuGet

32. Code sharing stats
Mac
iOS
Android
Windows Phone
iCircuit Touch Draw
86%
14%
72%
28%
70%
30%
61%
39%
88%
12%
76%
24%
90%
10%

33. Simplifying Development

34. Shared C# Backend

35. Platform
Specific Code
What if we didn’t have to
write this code?
What if we could access it
from shared code?
UI+APIs UI + APIsUI + APIs
Battery
GPS
Lights
Notifications
Settings
Text To Speech
Battery
GPS
Lights
Notifications
Settings
Text To Speech
Battery
GPS
Lights
Notifications
Settings
Text To Speech

36. TextToSpeech
Speak(“Hello World”);
AVSpeechSynthesizer SpeechSynthesizer

37. Plugins for Xamarin & Windows
Common API

38. Plugin Time

39. Cross-platform UI

40. Build native UIs for iOS, Android, and Windows
from a single, shared C# codebase.
Meet Xamarin.Forms

41. Xamarin + Xamarin.Forms
Traditional Xamarin approach With Xamarin.Forms:
More code-sharing, all native
iOS C# UI Windows C# UIAndroid C# UI
Shared C# Logic Shared C# Logic
Xamarin.Forms

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

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

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

45. Xamarin.Forms ecosystem

46. Native UI from shared code
<?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>

47. Xamarin.Forms
Shared C# Logic
Windows C#Android C#iOS C#

48. Getting Started Faster

49. Continuously deploy & debug apps
Xamarin Live Player

50. Xamarin Live Player Setup

52. Development with
Xamarin Live Player

53. Shared C# Logic
Android C# iOS C# tvOS C#macOS C# Linux C# Windows C# Web

55. Shared C#/.NET Logic
Android
Java
iOS
Swift
tvOS
Swift
macOS
Objective-C
Linux
C++
Jar/Aar DynamicLib Framework Framework C++

56. Get Started Today
Xamarin.com

57. Thank you.
James
Montemagno
Principal Program Manager – Mobile Developer Tools,
Microsoft
motz@microsoft.com motzcod.es @JamesMontemagno
Code:
http://github.com/jamesmontemagno/app-imagesearch-cogs