2019 .NET Mobile Development Hot Topics talk of GDL Community 2nd anniversary https://www.meetup.com/Guadalajara-Connect/events/258765783/

1. ALEJANDRO RUIZ
Microsoft MVP
alejandro@alejandroruizvarela.com
2019 .NET Mobile
Development Hot
Topics

2. 2019 the end of .NET mobile development?
2007 2008 2009-2011 2011 2013
20162014 2018 2019

3. Xamarin.Forms 3.4/3.5
• ImageButton
• BindableLayout
• Bindable Automation ID
• TabStop/TabIndex support
• Hide Scroll Bars on ListView
• And More…
• https://docs.microsoft.com/en-us/xamarin/xamarin-forms/release-
notes/

4. • As part of Microsoft efforts of creating a good mobile framework
Xamarin.Forms will be the major release based on community
feedback making the framework easy to use with a better way to
manage the navigation, have more consistent UI across iOS and
Android and a better and performance list control.
Xamarin.Forms 4.0

5. Shell – A Better Host for your Mobile App
Is a container for applications, that provides
fundamental UI features that most applications
require, leaving you to focus on the application's core
workload.
Shell applications are provided with the following
functionality:
• A single place to describe the visual structure of an
application
• A common navigation user interface.
• A navigation service with deep linking.
• An integrated search handler.

7. Consistent UI with Visual
• It’s possible today to create beautiful native applications for both
Android and iOS using Xamarin.Forms. You can even get them to look
much the same with styles, effects, custom renderers, and a generous
allotment of time. Visual aims to make this much, much easier by
providing a consistent control theme by default using Material(Google
Controls).
• Supported Controls: Button, Entry, Frame, and ProgressBar.

9. CollectionView is a view for presenting lists of data using different layout
specifications. It aims to provide a more flexible, and performant alternative
to ListView. While the CollectionView and ListView APIs are similar, there are some
notable differences:
• CollectionView has no concept of cells. Instead, data templates are used to define
the appearance of each item of data in the list.
• CollectionView reduces the API surface of ListView. Many properties and events
from ListView are not present in CollectionView.
• CollectionView has a flexible layout model, which allows data to be presented
vertically or horizontally, in a list or a grid.
Faster Lists, More Layouts

10. Horizontal & Vertical

11. Grid Layout

13. Try Xamarin.Forms 4 Now
https://docs.microsoft.com/en-us/xamarin/xamarin-forms/release-
notes/4.0/4.0.0-pre5

14. Android Build Performance & Reliability
D8 dexer and R8 shrinke
A typical Xamarin.Android APK file contains binaries compiled from
various languages:
• Java code: in an Android-specific DEX (Dalvik-executable) format
• C/C++ code: .so files such as the Mono runtime
• .NET code: .NET .dll files reside in an assemblies directory in the APK.

15. Android Build Performance & Reliability
Google recognized the performance implications of having to run several different tools to generate
DEX files. In 2017, Google announced D8 as a DEX compiler that was rewritten from the ground up
to perform many of these steps at once. The implications being that D8 could compile to DEX in 30%
less time and produce smaller DEX files than DX. D8 also implements “desugaring”, so it can accept
Java 8 code as input by default.
As an extension to D8, R8 is a Java code shrinker built as a replacement for ProGuard.

16. Result

17. Android Support Library v28
Starting with Xamarin’s Android Support Library version 28, multi-targeting
was introduced which includes assemblies for older support library versions when
your application’s TargetFrameworkVersion is lower than the expected version.
This will allow you to install the Android Support Library to your project regardless
of TargetFrameworkVersion and use the latest Android Support Library version that
is supported for your application.

18. Visual Studio 2019 Preview
• AI-Assisted XAML IntelliSense

19. • Smaller Workload Size
• Xamarin workload is now just 7.69GB, a 2x reduction from Visual Studio 2017 version 15.9 and a 3x
improvement over version 15.7.
• Android Emulator Improvements
• Easier to create new Android emulator images so you can debug your app
• Xamarin.Forms Property Panel
• You can now edit your Xamarin.Forms XAML control’s properties using the property panel inside of Visual
Studio 2019 for Windows
• Xamarin Android Designer Enhancements
• Drag and drop directly from the toolbox to the source editor
• You can select elements directly from their XML definition span in the source editor.
• Xamarin iOS Designer Enhancements
• Using PDF assets as an image source
• Color spaces and improved color precision
• Selecting named colors from asset catalogs
And Much More…

20. Try Visual Studio 2019 Preview Now
https://visualstudio.microsoft.com/vs/preview/

21. Questions?
Alejandro Ruiz
Microsoft MVP: Developer Technologies
2019 .NET Mobile Development Hot Topics
alejandro@alejandroruizvarela.com https://alejandroruizvarela.blogspot.mx @alejandroruizva

22. Thank You All

23. MFRACTOR License Raffle