Future Visions: Predictions to Guide and Time Tech Innovation, Peter Udo Diehl
Cross Platform Mobile Dev with C# and Xamarin 3 (RADNUG 8/19/14)
1. CROSS PLATFORM
MOBILE DEV WITH C#
AND XAMARIN 3
Ed Snider
Aug 19 2014
Rappahannock Area
Developers .NET Users
Group (RADNUG)
2. CONTENT
Introduction
The Problem with Native Mobile App Dev
The Benefits of Multi-Platform Mobile Dev with C#
How?
- MVVM
- Share Code
- Xamarin
Share UI Code w/ Xamarin.Forms
DEMO
3. INTRODUCTION
Ed Snider - @edsnider | www.edsnider.net
Developer at InfernoRed Technology
Co-Organizer of NoVA Mobile C# Developers’ Group
www.infernored.com
@infernoredtech
www.novamobiledev.org
@novamobiledev
4. THE PROBLEM WITH
TRADITIONAL NATIVE MOBILE
APP DEV…
Native mobile apps are great but here’s the problem:
Several Platforms: Windows, iOS, Android
Several Languages: C#, Objective-C, Java
Maintenance nightmares
Customers and end-users suffer
5. THE BENEFITS OF MULTI-PLATFORM
NATIVE MOBILE APP DEV
WITH C# Develop for all platforms with a single language – C# - using Xamarin
Harness the power of the .NET framework
Single solution with shared code
Unified and consistent maintenance/testing
Feature parity across platforms = happy end users
7. LEVERAGE THE MVVM
PATTERN
View (UI)
Data Binding
Commands
ViewModel
Model
Platform Specific
Service Implementations
Service
Interfaces
Connectivity
Location
Camera
Etc…
8. SHARE CODE!
Windows iOS Android
View / UI
View / UI
Platform Specifics
Platform Specifics
Portable Class Library (PCL)
ViewModels
Models
Core App Library
View / UI
Platform Specifics
Services, Business Logic, Service Access, Data Access, etc.
9. XAMARIN…
Xamarin is built on Mono
Allows native app compilation on Android and iOS using C#
100% API Coverage – All iOS and Android APIs
are exposed as C# class libraries
Up-to-date with API releases
from Apple and Google
16. XAMARIN.FORMS
Set of APIs that abstract platform specific UI elements and behaviors
Write UI code once and it is rendered natively across iOS, Android and Window Phone
Use C# and/or XAML
Ships as NuGet packages
Views can now live in the PCL
Mix and match with platform APIs
Shared UI Code
20. XAMARIN.FORMS VIEWS
Represents UI controls
Implemented natively and
platform specific
Entry = EditText on Android
Entry = UITextField on iOS
Entry = Textbox on Windows Phone
Xamarin.Forms Views
Documentation
21. SOME OTHER COOL THINGS
ABOUT XAMARIN…
Component Store: http://components.xamarin.com/
.NET Mobility Scanner: http://scan.xamarin.com/
F#: http://developer.xamarin.com/guides/cross-platform/
fsharp/fsharp_support_overview/
Xamarin Test Cloud: http://xamarin.com/test-cloud
22. RESOURCES
Xamarin.Forms Intro
http://developer.xamarin.com/guides/cross-platform/xamarin-forms/
introduction-to-xamarin-forms/
Code from my demo
https://github.com/edsnider/CoffeeFinder-XamarinFormsDemo
Image credit: https://octodex.github.com/
Notes de l'éditeur
If you are a windows developer you will be used to these name spaces.
These are the core .NET base libraries that we know and love.
If you mix in windows phone and windows store development you get new namespaces
Windows. And Microsoft. With platform specific APIs
Xamarin gives you the best of both worlds with full support for the .NET Framework (your System. Libraries)
Then they create C# bindings for every API in iOS and Android
As you can see here there are a few, CoreGraphics, CoreMotion, etc,
These are your platform specific bits to take advantage of everything in iOS
Then they do the same thing for Android so here you get the Android specifics
Renderscript, NFC to do cool phone tapping of data transfer
And text to speech apis to make your app shine
On iOS Xamarin Compiles the C# down to IL (intermediate language)
Then Xamarin create LLVM bit code
Then the LLVM bit code runs through the same LLVM Compiler and Optimizer that apple users for objective-c code
Creating the final native arm binary.
On Android they use an advanced compiler and linking to IL and
then JIT to create native instructions at runtime for optimal performance which often can be faster than the dalvik runtime.
