Chicago Coder Conference 2015 Building cross-platform native UIs with one shared codebase was once just a dream. With Xamarin.Forms, this dream is now a reality. Xamarin.Forms allows you to build a native UI for three platforms with one shared C# codebase. Simply put, if you know C# then you already know how to build iOS, Android, and Windows Phone apps. Leverage the .NET Framework to build out your shared business logic including integration with web services and Azure Mobile Services and then build out your shared UI in C# or XAML. Xamarin.Forms also features a built-in two-way data binding, dependency service to help you implement platform-specific code, an advanced cross-platform animation system, support for custom controls, and lots of other powerful features to help you build the best apps possible in the least amount of time. During this session we will cover the Xamarin platform and the brand new Xamarin.Forms library to share even more code across iOS, Android, and Windows Phone. Moreover, we will really focus on the code with several live coding adventures throughout the entire session. When you leave you will have the knowledge to create your first iOS, Android, and Windows Phone mobile apps in C# with Xamarin and Xamarin.Forms.

2. James
Montemagno
Developer Evangelist, Xamarin
james@xamarin.com http://motzcod.es @JamesMontemagno

3. DESIGN – DEVELOP -‐ INTEGRATE TEST MONITOR
LEARN

5. Native User Interfaces Native API Access Native Performance
? ? ?

7. -John Gruber
http://daringfireball.net/2015/05/facebook_instant_articles

9. iOS WindowsAndroid
Objective-C
Xcode
C#
Visual Studio
Java
AndroidStudio
No shared code • Many languages & development environments • Multiple teams

10. App Generator
Lua
Javascript
Actionscript
HTML+CSS
Limited native API access • Slow performance • Poor user experience

11. Shared C# codebase • 100% native API access • High performance
iOS C# UI Windows C# UIAndroid C# UI
Shared C# Mobile

12. Shared F# codebase • 100% native API access • High performance
iOS F# UI Windows F# UIAndroid F# UI
Shared F# Mobile

13. 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

14. MapKit UIKit iBeacon CoreGraphics CoreMotion
System.Data System.Windows System.Numerics System.Core System.ServiceModel
System.Net System System.IO System.Linq System.Xml

15. 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

16. 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.
.NET
C#
Compile
and Link
.APK
Bindings
Runs
Natively
IL
+
JIT

18. ✓Always Up-to-Date
•
•
•
•
•
•
•
•
•
•

20. Mac
iOS
Android
Windows Phone
Calca iCircuit Touch Draw
86%
14%
72%
28%
77%
23%
70%
30%
61%39%
94%
6%
88%
12%
76%
24%
90%
10%

22. Traditional Xamarin
Approach
With Xamarin.Forms:
More code-sharing, all native
iOS C# UI Windows C# UIAndroid C# UI
Shared C# Backend
Xamarin.Forms
Shared C# Backend

23. ✓ 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

24. Which Xamarin approach is
best for your app?
Xamarin.Forms is best for: Xamarin.iOS / Xamarin.Android is best for:
• Data entry apps
• Prototypes and proofs-of-concept
• Apps that require little platform-specific
functionality
• Apps where code sharing is more important
than custom UI
Learn more: xamarin.com/forms Learn more: xamarin.com/platform
• Apps that require specialized interaction
• Apps with highly polished design
• Apps that use many platform-specific APIs
• Apps where custom UI is more important
than code sharing

25. <?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>

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

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

28. Xamarin.Forms Ecosystem

30. Windows Xamarin.Forms
StackPanel StackLayout
TextBox Entry
ListBox ListView
CheckBox Switch
ProgressBar ActivityIndicator
Grid Grid
Label Label
Button Button
Image Image
Date/TimePicker Date/TimePicker

31. Windows Xamarin.Forms
DataContext BindingContext
{Binding Property} {Binding Property}
ItemsSource ItemsSource
ItemTemplate ItemTemplate
DataTemplate DataTemplate

35. Shared C# Backend

36. 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

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

38. Common API

40. Get Started Today
xamarin.com

41. xamarin.com/university
Unrivaled Mobile
Development
Training
Live unlimited mobile development training from
mobile experts, in your time-zone, on your
schedule, and as often as you'd like.

42. https://github.com/jamesmontemagno/TripExpenses.Forms
http://tryappservice.azure.com
https://components.xamarin.com/view/azure-mobile-services
http://github.com/xamarin/plugins
http://developer.xamarin.com

43. Thank you.
James
Montemagno
Developer Evangelist, Xamarin
james@xamarin.com http://motzcod.es @JamesMontemagno
Questions?