1.
Xamarin
Mobile Cross Platform Development

2.
bryan costanich
em: bryanc@xamarin.com
tw: @bryancostanich
slides: slideshare.net/bryancostanich

3.
Sample Code
github.com/xamarin/mobile-samples/TaskyPro
blog.xamarin.com

4.
Xamarin Platform
(The Pitch)

5.
One Language +
Framework
LINQ
Lambdas
Task Parallel Library (TPL)
Compile-Time Checks
Garbage Collection
C#
º

6.
Native Perf. + UX
Compiles Down to Native Code
Not Interpreted
All Native UX Controls
Full Platform SDK Access
iOS: Selectors/Obj-C Runtime
Android: JNI
Fast Enough for Games
º

7.
Reuse Story
C# Libraries
Obj-C Bindings + Binding Projects
.jar Bindings + Binding Projects
C via pInvoke
C++ via Cxxi
º

8.
Other Platforms
Windows - via .NET
Mac - via Xamarin.Mac
Linux - via Mono
Ouya, XBOX, PSP, etc.
Etc.

9.
Community +
Support
Huge C# Community
StackOverflow.com
forums.xamarin.com
IRC + chat.xamarin.com
Great Support
º

10.
VS + Xamarin
Studio
Visual Studio
Xamarin Studio
Android Designer
iOS Designer (Beta)
Debugging
AutoComplete
Refactoring
Project Management
Integrated Source Control

11.
General XPlat Considerations

12.
Design Platform-Specific UX
UX in iOS != Android != Windows
Phone
UX Metaphors are Different:
Navigation Controller vs. Back
Button
Write-Once, Run-Anywhere is
Problematic
Users Expect Native UX
º

13.
Choose Device
Targets
iPhone != iPad
Beware Android Fragmentation
Form Factor + Capability Differences
Inform UX
Pro-Tip: Minimize Targets
º

14.
Building an X-Plat Architecture

15.
Architecture
Layers
Separation of Responsibility
Encapsulation
Core Code Sharing
º

16.
VS Project/Solution Setup

17.
Code Sharing - Linking vs. PCL
Portal Library Projects - Take a Lot of Work
Great Discussion Here:
http://forums.xamarin.com/discussion/28/challenges-thoughts-loves/p1
Takeaway:
PCL is clean, but difficult to implement
Linking is less “clean” but simpler
Our Recommendation Now: File Linking for Most Projects
Walkthrough Here: Linking
º

18.
WP7 + Android
New Blank Solution: "[AppName]"
New C# Lib Project: "[AppName].Core"
Test Project: “[AppName].Core.Tests”
New Mono for Android Project: “[AppName].Droid”
New WP7 Project "[AppName].WP7"
º

19.
Shared Data +
Data Access
Layer
Data Access
Layer
SQLite on iOS + Android, C# SQLIte on WP7:
http://code.google.com/p/csharp-sqlite/
SQLite.NET ORM
Use Generics for CRUD Convenience Methods:
TaskDatabase.cs
º

20.
Platform Abstractions
Handling Divergence and Taking Advantage of Platform
Features

21.
Conditional
Compilation
Pre-Defined Symbols:
#if __MOBILE__
#if __ANDROID__
#if __IOS__
#if WINDOWS_PHONE
#if SILVERLIGHT
Can Add Additional in Build Settings

22.
Architectural
Abstraction
Sometimes, You Wanna Provide
Different Implementations for Different
Platforms
Interfaces
º

23.
Component Store
Tons of Components
Cross-Platform
IDE-Integration - drop-in!
Revenue Model for User
Submitted

24.
Xamarin.* Libraries
XPlat API Abstractions
Open Source
Github.com/Xamarin/Xamarin.*
Mobile Social Auth

25.
Other XPlat Libs
MonoCross - http://code.google.com/p/monocross/
MvvmCross - https://github.com/slodge/MvvmCross
Vernacular - https://github.com/rdio/vernacular
MonoGame - http://monogame.net
Cocos2D - http://cocos2DXNA.net
º

26.
Q+A