Creating Cross-Platform C# Applications with Uno Platform: Build apps with C# and XAML that run on Windows, macOS, iOS, Android, and WebAssembly

BIRMINGHAM—MUMBAI

Creating Cross-Platform C# Applications with Uno Platform

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Contributors

About the authors

Matt Lacey has been building desktop and mobile software since the '90s. He currently works as an independent development consultant and focuses on helping developers to create better software. Having worked in companies of all sizes and in a wide variety of industries, he brings this breadth of experience to present a viewpoint that considers technology, business, and design.

Matt is a Microsoft MVP in Windows Development, regularly speaks at user groups and conferences in multiple countries, and is a prolific contributor to a plethora of open source projects. He lives in the UK with his wife and two children.

Marcel Alexander Wagner is a full-stack software developer and open source contributor. He is a Microsoft MVP in Windows Development and a top contributor to the WinUI library and the XAML Controls Gallery, while also contributing to other projects and libraries, including the Windows Community Toolkit and Uno Platform.

Marcel graduated with a Bachelor of Science in computer science and has since been developing applications and services with a wide variety of technologies, including React, Java, C#, C++, UWP, and Uno Platform. He currently resides in Germany.

About the reviewers

David Oliver is an open source framework developer with a .NET background. He is a recovering physicist and lapsed Australian. He is currently a senior developer on the Uno Platform core team.

Martin Zikmund is a freelance software developer and Microsoft Developer Technologies MVP. He specializes in building cross-platform mobile and cloud solutions on the Microsoft technology stack. His passion is contributing to open source, especially to Uno Platform. You can also encounter him on Stack Overflow, where he frequently helps other developers. To document his developer journey, Martin regularly writes articles on his blog and tweets about interesting things he comes across. In his spare time, he likes to play squash, game on Xbox, read, and search for geocaches.

Nick Randolph currently runs Built to Roam, which focuses on building rich mobile applications. He has been identified as a Microsoft MVP in recognition of his work and expertise with Microsoft application platforms.

Nick is an active contributor in the device application development space via his blog. He has been invited to present at a variety of events, including TechEd and Ignite Australia and NZ, DDD, NDC, and local user groups. He has also authored multiple books on Visual Studio and Windows development.

Shimmy Weitzhandler is a skilled full-stack developer and consultant working independently.

He has been coding for nearly two decades, and has used technologies ranging from ASP.NET, HTML, and JavaScript with VB.NET to WPF, Silverlight, WinUI, and, for the past few years, Uno Platform.

Among his projects are an emergency response system, a club card management and points accumulation portal, video conversion software, a school and college system, e-commerce websites, and QuickBooks components.

Shimmy is an active member and contributor on key tech hubs such as GitHub and Stack Overflow.

He is well known for his distinct programming style, his architectural thinking, and his dedication to creativity and transparency, utilizing the latest technologies.

Table of Contents

Preface

Section 1: Getting to Know Uno Platform

Chapter 1: Introducing Uno Platform

Technical requirements

Understanding what Uno Platform is

A brief history of Uno Platform

How Uno Platform works

Is it a panacea?

Using Uno Platform

Uno Platform allows you to use what you already know

Uno Platform supports many platforms

Can Uno Platform do everything that your app requires?

How does Uno Platform compare to the alternatives?

Setting up your development environment

Developing with Visual Studio

Using other editors and IDEs

Checking your setup

Debugging your setup

Summary

Further reading

Chapter 2: Writing Your First Uno Platform App

Technical requirements

Creating your first app

Creating your project with the Uno Platform solution templates

Creating your project with the .NET CLI

Project structure and the heads

Building and running your first Uno Platform app

Running and debugging your app with Visual Studio on Windows

Running and debugging your apps with Visual Studio for Mac

Debugging the WASM head of your app

XAML Hot Reload and C# Edit and Continue

Platform-specific XAML and C#

Platform-specific C#

Platform-specific XAML

Going beyond the default cross-platform app structure

The multi-platform library project type

Other project types

Summary

Section 2: Writing and Developing Uno Platform Apps

Chapter 3: Working with Forms and Data

Technical requirements

Introducing the app

Creating the app

Entering and validating data

Using Windows Community Toolkit controls

Displaying data using DataGrid

Displaying data with the DataGrid control

Exporting issues in PDF format

Exporting on desktop

Exporting on the web with a download link

Summary

Chapter 4: Mobilizing Your App

Technical requirements

Introducing the app

Creating the app

Creating the main page

Showing upcoming arrival details

Retrieving remote data

Connecting to a remote data source

Using Polly to handle exceptions and retry requests

Making your app look like it belongs on each platform

Applying Material styles to the Android version of the app

Applying Cupertino styles to the iOS version of the app

Accessing device capabilities

Summary

Chapter 5: Making Your App Ready for the Real World

Technical requirements

Introducing the app

Creating the app

Creating the main navigation and booking process

Persisting data locally using the ApplicationData API and SQLite

Storing data using the ApplicationData API

Using SQLite to store data

Loading data from SQLite

Making your app ready for customers

Localizing your app

Customizing your app's appearance

Ensuring everyone can use your app

Summary

Chapter 6: Displaying Data in Charts and with Custom 2D Graphics

Technical requirements

Introducing the app

Creating the app

Creating the individual pages

Creating the main page

Displaying charts with controls from SyncFusion

Updating references to include the SyncFusion controls

Drawing a line chart

Displaying charts with controls from Infragistics

Updating references

Drawing a column chart

Drawing custom graphics with SkiaSharp

Updating project references

Drawing the network map

Responding to changes in the UI

Changing the page layout

Stretching and scaling content to fit the available space

Summary

Section 3: Test, Deploy, and Contribute

Chapter 7: Testing Your Apps

Technical requirements

Getting started with Uno.UITest

Writing and running your first test

How Uno.UITest works

Authoring your first test

Running your tests on Android, iOS, and WASM

Writing more complex tests

Test tools beside Uno.UITest

Testing the UWP head of your app with WinAppDriver

Writing unit tests for your Uno Platform app

Performing manual testing and why it is important

Summary

Chapter 8: Deploying Your Apps and Going Further

Technical requirements

Bringing Xamarin.Forms apps to WebAssembly

Deploying a Wasm Uno Platform app to the web

Automating build, tests, and distribution

Deploying your app to a store

Engaging with the Uno Platform community

Sources of information

Sources of help

Contributing

Summary

Other Books You May Enjoy

Preface

Developers are increasingly being asked to build native applications that run on multiple operating systems and in the browser. In the past, this would have meant learning new technologies and making multiple copies of an application. But Uno Platform allows you to use tools, languages, and APIs you already know from building Windows apps to develop apps that can also run on other platforms. This book will help you to create customer-facing as well as line-of-business apps that can be used on the device, browser, or operating system of your choice.

This practical guide enables developers to put their C# and XAML knowledge to work by writing cross-platform apps using Uno Platform. Packed with tips and practical examples, this book will help you to build applications for common scenarios. You'll begin by learning about Uno Platform through step-by-step explanations of essential concepts, before moving on to creating cross-platform apps for different lines of business. Throughout this book, you'll work with examples that will teach you how to combine your existing knowledge to manage common development environments and implement frequently needed functionality.

By the end of this Uno Platform development book, you will have learned how to write your own cross-platform apps with Uno Platform and use additional tools and libraries to speed up your app development process.

Who this book is for

This book is for developers who are familiar with app development for Windows and want to use their existing skills to build cross-platform apps. Basic knowledge of C# and XAML is required to get started with this book. Anyone with basic experience of app development using WPF, UWP, or WinUI will be able to learn how to create cross-platform applications with Uno Platform.

What this book covers

Chapter 1, Introducing Uno Platform, introduces the Uno Platform, explaining what it is designed for and when to use it. After this, the chapter will cover how to set up the development machine and install the necessary tools.

Chapter 2, Writing Your First Uno Platform App, walks through creating your first Uno Platform app and covers the app's structure. By the end of this chapter, you will have written a small Uno Platform app that can be run on different platforms and display content based on the OS the app is running on.

Chapter 3, Working with Forms and Data, walks you through developing a data-focused line-of-business app for the fictional company UnoBookRail. The chapter covers displaying data, providing input validation on forms, and exporting data to PDF.

Chapter 4, Mobilizing Your App, introduces you to developing mobile apps using Uno Platform. In addition to that, the chapter covers working with remote data on devices with unstable internet connections, styling the app based on the platform it is running on, and using device capabilities such as the camera.

Chapter 5, Making Your App Ready for the Real World, covers writing a mobile app that is aimed at external customers. As part of this, it covers persisting data locally on the device, localizing your app, and writing an accessible app with Uno Platform.

Chapter 6, Displaying Data in Charts and with Custom 2D Graphics, explores displaying graphs and charts in an Uno Platform app. The chapter covers using libraries such as SyncFusion and creating custom graphics using SkiaSharp. Lastly, the chapter covers writing a UI that responds to changes in screen size.

Chapter 7, Testing Your Apps, introduces you to UI testing with Uno.UITest. In addition, this chapter covers writing automated UI tests with WinAppDriver, writing unit tests for the Windows 10 version of the app, and testing the app for accessibility.

Chapter 8, Deploying Your Apps and Going Further, walks you through bringing your Xamarin.Forms app to the web with Uno Platform and deploying WASM Uno Platform apps to Azure. After this, the chapter covers deploying an Uno Platform app and joining the Uno Platform community.

To get the most out of this book

In this book, we will be using Visual Studio 2019 on Windows 10 and the .NET CLI to develop Uno Platform apps. We will cover installing the necessary extensions and CLI tools; however, installing Visual Studio and the .NET CLI will not be covered. To install the required software, you will need a functional internet connection.

If you are using the digital version of this book, we advise you to type the code yourself or access the code from the book's GitHub repository (a link is available in the next section). Doing so will help you avoid any potential errors related to the copying and pasting of code.

Download the example code files

You can download the example code files for this book from GitHub at https://github.com/PacktPublishing/Creating-Cross-Platform-C-Sharp-Applications-with-Uno-Platform. If there's an update to the code, it will be updated in the GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Code in Action

The Code in Action videos for this book can be viewed at https://bit.ly/3yHTfYL

Download the color images

We also provide a PDF file that has color images of the screenshots and diagrams used in this book. You can download it here: https://static.packt-cdn.com/downloads/9781801078498_ColorImages.pdf.

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: Inside the UnoAutomatedTestsApp folder, create a folder named UnoAutomatedTestsApp.UITests.

A block of code is set as follows:

private void ChangeTextButton_Click(object sender,

                                    RoutedEventArgs e)

{

    helloTextBlock.Text = Hello from code behind!;

}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

xmlns:skia=using:SkiaSharp.Views.UWP

PaintSurface=OnPaintSurface />

Any command-line input or output is written as follows:

dotnet new unoapp -o MyApp

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: Open the Test Explorer by clicking View in the menu bar and clicking on Test Explorer.

Tips or important notes

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Get in touch

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