Starting Out Right with Xamarin

Starting Out Right with Xamarin

20 18 ED IT IO N Starting out right with Xamarin and other useful tips, tricks and resources p.s. still just my opinion RYAN DAVIS QUEENSLAND C# MOBILE DEVELOPERS MEETUP 2018 09 25

whoami Ryan Davis Professional Mobile LINQPad Developer Blog: Twitter: @rdavis_au Github: @rdavisau essential-interfaces use DI/mocking with Xamarin.Essentials jsondatacontext-linqpad json data context driver for LINQPad sockets-for-pcl, sockethelpers socket comms in a PCL (today you should use netstandard sockets why are you all still installing this) to cover File -> New Mobile principles to live by

Pop Quiz your first big questions Spotlight on some useful libraries Roundup of resources. # 1 -= mobile principles to live by =- know platform love thy neighbour

why Xamarin, again? (yeah this list isnt really MECE) Xamarin because: Write code in powerful, expressive languages Take advantage of the .NET platform and ecosystem TARGET ALL THE PLATFORMS!! Share as much code as we can Avoid Java and Objective-C and swift Dont want to learn about the native platforms. not all mobile platforms are created equal

Xamarin is not designed to relieve you of the need to understand the underlying platform: Android, iOS and UWP differ on many levels UI, app lifecycle, sandboxing Each platform might be more or less suited to a task or paradigm Xamarin.Forms abstracts some of these platform variations, some of the time. fortunately, we can make use of native docs Xamarins iOS/Android frameworks are C# idiomatic, but otherwise near identical to native ObjC/Swift/Java counterparts A book or course targeting iOS or Android native is still relevant, especially for frameworks like UIKit and CoreAnimation Tutorials and documentation are easily adapted

The balance of swift objc samples has tipped over the last couple of years Probably the biggest deviation from native API naming: - tableView:cellForRowAtIndexPath: NATIVE iOS GetCell(,) XAMARIN iOS # 2

-= mobile principles to live by =- crossplatform ^ begin with the end in mind Forms or otherwise, MVVM is a safe bet The components of MVVM map closely to the original code sharing architecture in a Xamarin app, and the ecosystem has evolved around that. Native Project

Native Project Portable Class Library Native Project From a Xamarin From a google image result for MVVM go MVVM with netstandard from the beginning

(even if you focus on a single platform first) Keeping your viewmodels in the core project and your views TM in native projects* encourages Good Habits You cannot accidentally use platform-specific and non-netstandard APIs You cleanly separate your viewmodel and views, and your code goes into the viewmodel by default . * In Xamarin.Forms projects, a dedicated UI project gives you the same separation and benefits # 3

-= mobile principles to live by =- dependencies keep your liabilities closer mobile moves fast, libraries age faster Xamarin lends itself to libraries and abstractions, and there are many Libraries can got stale for lots of reasons, some particular to the Xamarin/Mobile Mobile itself moves quickly and changes frequently something that works today may be deprecated or disallowed in a years time. think carefully about adding

dependencies When the next android SDK deprecates features in your dependencies, or you want to bump your target version, what will you do if your libraries havent been updated? If your dependencies move to newer API versions before you are ready, how can you incorporate important bugfixes or new features? If you discover a bug in an abandoned library that youre already shipping, how will you prevent it from affecting your users? With OSS, we have options A private NuGet feed to host builds from forks can help out in a pinch e.g. uptarget or downtarget a dependency Incorporate a bugfix that the maintainer hasnt merged Add InternalsVisibleTo(yourproject) a library (if you are feeling brave)

Consider how to best contribute fixes or changes back to mainline repos. # 4 -= mobile principles to live by =- win friends and influence peo aka. get involved in the community Xamarin has a great core community For newcomers, it can be hard to know whats out there, which libraries are reliable, etc. it can help to start following the work of

others Twitter is a popular platform amongst Xamarin and .NET developers For a good summary of whats happening, subscribe to the Weekly Xamarin Newsletter Z I U Q PO P Answering the tough questions

Q1: your next cross platform mobile app Q1: your next cross platform mobile app NATIV E VS WEB Q2: To Share UI, or not to Share UI Xamari n

or Xamarin.For ms Q2: To Share UI, or not to Share UI Xamari n or Xamarin.For ms Forms has been improving steadily over the years and is now open source

You can do nice UIs with Forms: jsuarezruiz/xamarin-forms-goodlooking-UI Forms Embedding is a Great Thing Which You Should Definitely Use see Alex Dunns posts for some techniques (iOS, Droid) Q2: To Share UI, or not to Share UI jsuarezruiz/xamarin-forms-goodlooking-UI SmartHotel BikeSharing Q2: To Share UI, or not to Share UI Xamari n or

Xamarin.For ms If you want flexibility: use a native shell with first class support for embedding Keep Xamarin.Forms off the startup path Full native control over screen transitions and exterior elements Use viewmodel-first navigation and centralise your forms<->native smarts there (including XF initialisation) Even the most UI intensive apps can likely benefit from a few forms pages Q3: or new UI(); XAML/ Designer

or Coded UI Q3: or new UI(); XAML/ Designer or Coded UI But either is cool Q3: or new UI(); XAML/

Designer or Coded UI But either is cool Q3: or new UI(); - iOS XAML/ Designer Storyboards Single file containing screens + transitions Many new features including static tableview content and prototype cells

Source control nightmare XIBs File per view easy reuse, source control New features not supported Both Coded UI Coded UI Anything is possible dynamic layouts, subclassing/reuse No magic you control how and when your view is created Writing constraints in code can be arduous DSLs (e.g. FluentLayout, EasyLayout+) help

No design-time/preview unless you use something like Continuous I like coded Q3: or new UI(); - Android XAML/ Designer AXML The right way to do Android UI If you have trouble with the Xamarin.Android designer you can use the Android Studio one. Coded UI Coded UI

Not impossible, just not advisable Some discussion here Q3: or new UI(); Xamarin.Forms XAML/ Designer XAML Good tooling support in wrt previewer and live reloader. On VS4Mac, Mfractor adds many significant QoL and productivity enhancements to the XAML experience in particular XF developer mindshare tends towards XAML-based views

Coded UI Coded UI Anything is possible Some constructs can be more verbose to specify in code Some constructs can be less verbose to specify in code No design-time/preview unless you use something like Continuous Use CSharpForMarkup and thank Vincent later I like coded Q4: Which IDE Visual

Studio Resharper UWP Generally better editor experience (IMO) Consolidate NuGet packages VS VS4Mac MFractor Better iOS experience designer, build/deploy Some features come to mac later than win I use both

Q5: Your dev machine and you Parallel s VS Bootcamp ESX VS Hyper-V Q5: Your dev machine and you

The true challenge of cross platform: You need a Mac to build/run iOS apps You need to be running Windows + Hyper-V to run the UWP device emulator Android is chill and runs everywhere, thanks buddy hey NBD What can we do? If you want to keep your options open, a Mac is a safe expensive bet Use Bootcamp, you can boot Windows direct or use Parallels/VMWare from OSX (Parallels seems to perform best, this result has been consistent for several releases now) If youre brave, you can also boot your OSX partition in VMWare when

t h g i l t o p S on some cool libraries I ran out of time there are only 2

how to use HttpClient to query a JSON API Step 1:Reconsider. hello Refit Refit gives you automatic type-safe api client generation Create an interface for your API, annotated with verb and URL stem Type-safe API methods, async, (de)serialization come for free! Supports all the best verbs, body parameters, authentication, static and dynamic request headers and generic interface definitions. Publish an internal nuget package with your Refit api definitions on every change and

have strongly-typed access to your apis from anywhere (e.g. in linqpad) persisting data Akavache Akavache gives you async-friendly key-value persistence + more Has a GetAllObjects() method Facilitates caching and expiry: GetOrFetchLatest(string key, Func, DateTimeOffset expiry) Add encryption using this one simple trick [link] This tutorial shows you how to do the same using a randomly generated encryption key stored in the keychain (rather than relying on user input) [link] this implementation assumes all inputs (serialised values) will be under the (block size padding length: 256 11 = 245 bytes), If you are storing larger payloads you can use the `CreateEncryptedData` method on iOS and a technique like [this] on android super duper animations - lottie

Lottie renders Adobe After Effects animations exported as json with Bodymovin, giving you high performance animations for little effort Support for iOS and Android natively, or via Xamarin.Forms Many animations available at for inspiration Great for keeping onboarding flows simple but impressive cross platform apis with no fuss essentials Xamarin.Essentials provides easy access to cross-platform APIs for mobile applications. Accelerometer App Information Battery Clipboard Compass Connectivity

Data Transfer (Share) Device Display Information Device Information Email File System Helpers

Flashlight Geocoding Geolocation Gyroscope Launcher Magnetometer

MainThread Maps Open Browser Orientation Sensor Phone Dialer Power Preferences If you like interfaces, try Essential.Interfaces too!

Screen Lock Secure Storage SMS Text-to-Speech Version Tracking Vibrate y even xaml am I rite CSharpForMarkup is a small set of extensions designed to make writing Forms UI in code fluent and more declarative. XAML C# (XAML-like) C# (concise)

Simple helpers that make coded-ui life easier: Execute code inline Assign controls inline Enum-based row/cols Resource roundup docs/learning Xamarin Docs

Xamarin University Books Mastering Xamarin.Forms - Xamarin in Action - You, I and ReactiveUI -

Creating Mobile Apps with Xamarin.Forms (social) media Xamarin MVP List Public Xamarin Slack Planet Xamarin blog aggregation Xamarin Gitter channels iOS/MacOS: xamarin/xamarin-macios

Android: xamarin/xamarin-android Forms: xamarin/Xamarin.Forms Subscribe to the Weekly Xamarin Newsletter! frameworks/libraries MVVM MvvmCross - Popular cross-platform MVVM library, Native/Forms

ReactiveUI - Reactive Extensions and FRP principles, Native/Forms MVVM Light Toolkit - Light MVVM, Native/Forms Prism - - Forms FreshMvvm - Forms Libraries from the previous section

Akvache - - An asynchronous, persistent key-value store Refit - - The automatic type-safe REST library for Xamarin and .NET Lottie - - Beautiful animations in mobile apps Xamarin.Essentials - - Cross platform APIs for mobile

CSharpForMarkup - - Fluent, declarative coded UI for XF frameworks/libraries (continued) Library Roundups Awesome Xamarin - Awesome Xamarin.Forms -

Goodlooking Xamarin.Forms - game dev UrhoSharp UrhoSharp [repo] Docs [official Xamarin documentation]

Introduction to UrhoSharp presentation Virtual/Mixed Reality Apps with C# [Build 2017 session] Urho3d [official website] ci/cd App Center [official website] Docs [official Xamarin documentation] Introduction to Visual Studio App Center presentation Azure DevOps

Step by step guides for setting up Xamarin Builds [james montemagnos blog posts] Misc Mobile.BuildTools [helper library for CI tasks and Xamarin Projects] native platforms iOS Ray Wenderlichs site -

iOS Dev Weekly - iOS Dev Center [apples own] - Droid [its official] - + approximately 999,999,999,999 courses on Pluralsight

podcasts/videos The Xamarin Show - Merge Conflict - Gone Mobile - questions / thanks

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