Building Windows phone, iOS and Android apps with C# Jaime Rodriguez Principal Evangelist, Microsoft

About me Why this talk…. 90s Today Primitive s Productivit y UX Mobile Disclaimer

About me Why this talk…. 90s Today Primitive s Productivit y UX Mobile Disclaimer I do not work for Xamarin Opinions are my own, not those of my day-job employer This space evolves very fast

Mobile Explosion Consumers are already mobile-first Business users are increasingly demanding mobile scenarios

How? #1 – Web Build a Mobile Website

How? #2 – Hybrid Web Put a Web App In the Store Native App Mobile Website

How? #3 – Cloned Native Build App Multiple Times

How? #4 – Shared Native Shared UI Code Build Natively and Share Code

With Visual Studio you can … Use a single development environment to target all devices Leverage your skills in your preferred language, C# or JavaScript Get the best developer experience for editing, building and debugging your applications

Why Native? Xamarin apps look and feel native because they are native Native User InterfacesNative API AccessNative Performance

Start with C# and BCL

… add Windows APIs 100% coverage

… or iOS APIs 100% coverage

… or Android APIs 100% coverage

demo Xamarin Development with Visual Studio

@implementation MSViewController - (void)viewDidLoad { [super viewDidLoad]; } - (IBAction)OnButtonDown:(id)sender { UIAlertView* view = [[UIAlertView alloc]init]; [view World"]; [view are you?”]; [view [view show]; public partial class iOSAppViewController : UIViewController { public iOSAppViewController (IntPtr handle) : base (handle){ } public override void ViewDidLoad (){ base.ViewDidLoad (); } partial void OnButtonDown (UIButton sender) { UIAlertView view = new UIAlertView(); view.Title = "Hello World" ; view.Message = "How are you? " ; view.AddButton ("OK"); view.Show(); } } iOS

public class MyActivity extends Activity public void onCreate(Bundle savedInstanceState) { Button myBtn = (Button) this.findViewById( R.id.clickMe); myBtn.setOnClickListener( new View.OnClickListener() public void onClick(View view) { AlertDialog.Builder builder = new AlertDialog.Builder(MyActivity.this) ; builder.setTitle( "Hello World").setMessage("How are you?").setPositiveButton( "OK", new DialogInterface.OnClickListener() public void onClick(DialogInterface dialogInterface, int i) { dialogInterface.dismiss(); }}).show(); }}); } } [Activity (Label = "AndroidApp", MainLauncher = true, Icon = public class MainActivity : Activity { protected override void OnCreate (Bundle bundle) { base.OnCreate (bundle); SetContentView (Resource.Layout.Main); Button button = FindViewById (Resource.Id.me); button.Click += delegate { AlertDialog.Builder builder = new AlertDialog.Builder (this ); AlertDialog dialog = null ; builder.SetTitle ( "Hello World").SetMessage ( "How are you").SetPositiveButton( "OK", delegate { dialog.Dismiss(); } ); dialog = builder.Show (); } ; } } Android

Anything you can do in Objective-C or Java can be done in C# with Xamarin using Visual Studio

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.

So far… Using C# BCL on iOS, Android and Windows Phone apps C# Bindings to iOS/Android Great tooling Editors Debugging Extensibility Potentially cumbersome code sharing as you write platform specific code ?

Sharing v1 Really?

Linked Files Compiler Directives

Code sharing v3

Share Code: Portable Class Libraries

NuGet

Shared Projects

UI: Xamarin + Xamarin.Forms With Xamarin.Forms: more code-sharing, native controls Traditional Xamarin approach Shared UI Code

 40+ Pages, Layouts, and Controls  Build from code behind or XAML  Two-way Data Binding  Navigation  Animation API  Dependency Service  Messaging Center UI: Xamarin.Forms Shared UI Code

Pages ContentMasterDetail NavigationTabbedCarousel

Layouts Stack AbsoluteRelativeGrid ContentViewScrollView Frame

Controls ActivityIndicator BoxViewButtonDatePickerEditor EntryImageLabelListViewMap OpenGLViewPickerProgressBarSearchBarSlider StepperTableViewTimePicker WebViewEntryCell ImageCellSwitchCellTextCellViewCell

Xamarin Forms Mark-up (XAML 2009 spec) Data binding & Data Templates Markup Extensions Resources Dictionaries

Xamarin Forms Platform Features Page.DisplayAlert UI Thread marshalling Timers Xamarin.Forms.Maps Platform code via OnPlatform and DependencyService.Get

demo Hacking away with Xamarin and Visual Studio

Tips & Tricks Personal Observations & Lessons learned

Ramp-up & Mastery To be successful using C# on iOS, Android, and Windows Phone, you still have to know how to code for these platforms

How I learned native…

How I learned Xamarin…

Sharing code… what should you use? a)PCL b)Shared Projects c)partial classes d)C# extensions e)All of the above

UI Patterns & Tips Separate your concerns Declarative XAML MVVM is not required Use OnPlatform for platform specific code Use ContentPage + layout panels for dynamic resolution

Connect to the cloud: Microsoft Azure

Memory & Garbage Collection iOS Uses AOT (Ahead of Time) compiler Two GCs: default (Boehm) or Sgen Android Uses Sgen GC Windows Phone Uses.NET GC,

Performance Is usually not a problem Use native tools to measure iOS: Instruments Android: Device Monitor’s Allocation Manager Windows Phone: Visual Studio, Windows Phone Power tools, Graphics Diagnostics

For gamers

Closing: Mobile app development with C# Familiar Productive Highly reusable Empowering Built on a solid and extensible foundation

Want to win a free Xamarin license? 1.Download free version of Xamarin Studio … 2.Create a small Hello World Project on at least two of the three platforms: Windows Phone, Android, iOS. 3.Tweet a link to your project before October 10 th at noon PST 4.One random submission will be selected….and a coupon for free license will be ed

Gracias!!! Aqui estoy los tres