1 Introducing Apps and Services with .NET

In this first chapter, the goals are setting up your development environment to use Visual Studio, VS Code, or Rider, and understanding your choices for building apps and services. We will also review good places to look for help.The GitHub repository for this book has solutions using full application projects for all code tasks:https://github.com/markjprice/apps-services-net10/After going to the GitHub repository, simply press the . (dot) key on your keyboard or change .com to .dev to change the repository into a live code editor based on VS Code using GitHub Codespaces. VS Code in a web browser is great to view the solution code (read-only) alongside your chosen code editor as you work through the book’s coding tasks. You can compare your code to the solution code and easily copy and paste parts to save time entering the code manually.Throughout this book, I use the term modern .NET to refer to .NET 10 and...

Introducing this book and its contents

This book caters to two audiences:

Readers who have completed my book for beginners, C# 14 and .NET 10 – Modern Cross-Platform Development Fundamentals, or an earlier edition, and now want to take their learning further.
Readers who already have basic skills and knowledge about C# and .NET and want to learn practical skills and knowledge to build modern apps and services using popular libraries and databases.

Companion books to complete your learning journey

This is one of four books in a quartet that provides a learning journey through .NET 10:

The first book covers the fundamentals of the C# language, the .NET libraries, and modern ASP.NET Core technologies for web development. It is designed to be read linearly because skills and knowledge from earlier chapters build up and are needed to understand later chapters.
The second book covers mature and proven web development technologies like ASP.NET Core MVC and controller-based Web API...

App and service technologies

Microsoft calls platforms for building applications and services app models or workloads.

Understanding .NET

.NET, .NET Core, .NET Framework, and Xamarin are related and overlapping platforms for developers used to build apps and services. If you are not familiar with the history of .NET, then I will point you to each of these .NET concepts at the following link, which is from the C# 14 and .NET 10 – Modern Cross-Platform Development Fundamentals book:

https://github.com/markjprice/cs14net10/blob/main/docs/ch01-dotnet-history.md

Building Windows-only desktop apps

Technologies for building Windows-only desktop apps include:

Windows Forms, 2002
Windows Presentation Foundation (WPF), 2006
Windows Store, 2012
Universal Windows Platform (UWP), 2015
Windows App SDK (formerly WinUI 3 and Project Reunion), 2021

Understanding legacy Windows application platforms

With the Microsoft Windows 1.0 release in 1985, the only way to create Windows applications...

Setting up your development environment

Before you start programming, you’ll need a code editor for C#. Microsoft has a family of code editors and Integrated Development Environments (IDEs), which include:

Visual Studio (for Windows-only)
VS Code (for Windows, Mac, or Linux)
GitHub Codespaces (for cloud-based coding)

Third parties have created their own C# code editors, for example, JetBrains Rider, which is available for Windows, Mac, or Linux. Since October 2024 it has a free version that you can read about at the following link: https://blog.jetbrains.com/dotnet/2024/10/16/rider-reveal-livestream-big-news-for-dotnet-and-game-devs/. Rider is popular with more experienced .NET developers.

Warning! Although JetBrains is a fantastic company with great products, both Rider and the ReSharper extension for Visual Studio are software, and all software has bugs and quirky behavior. For example, they might show errors like “Cannot resolve symbol” in your Razor Pages, Razor...

Exploring top-level programs, functions, and namespaces

Since .NET 6, the default project template for console apps uses the top-level program feature introduced with .NET 5. It is important to understand how it works with the automatically generated Program class and its <Main>$ method.Let’s explore how the top-level program feature works when you define functions:

Use your preferred coding tool to create a new project, as defined in the following list:
Project template: Console App / console
Project file and folder: TopLevelFunctions
Solution file and folder: Chapter01
Do not use top-level statements: Cleared
Enable native AOT publishing: Cleared
In the TopLevelFunctions.csproj project file, treat warnings as errors, and then globally and statically import the System.Console class, as shown highlighted in the following markup:

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework...

Making good use of the GitHub repository for this book

Git is a commonly used source code management system. GitHub is a company, website, and desktop application that makes it easier to manage Git. Microsoft purchased GitHub in 2018, so it will continue to be closely integrated with Microsoft tools.I created a GitHub repository for this book, and I use it for the following:

To store the solution code for the book, which will be maintained after the print publication date.
To provide extra materials that extend the book, like errata fixes, small improvements, lists of useful links, and longer articles that cannot fit in the printed book.
To provide a place for readers to get in touch with me if they have issues with the book.

Raising issues with the book

If you get stuck following any of the instructions in this book, or if you spot a mistake in the text or the code in the solutions, please raise an issue in the GitHub repository:

Use your favorite browser to navigate to the following...

Where to go for help

This section is all about how to find quality information about programming on the web.

Reading documentation on Microsoft Learn

The definitive resource for getting help with Microsoft developer tools and platforms is in the technical documentation on Microsoft Learn, and you can find it at the following link: microsoft.com/en-us/docs.

Getting help for the dotnet tool

At the command prompt, you can ask the dotnet tool for help with its commands. The syntax is:

dotnet help <command>This will cause your web browser to open a page in the documentation about the specified command. Common dotnet commands include new, build, and run.

Warning! The dotnet help new command worked with .NET Core 3.1 to .NET 6, but it returns an error with .NET 7 or later: Specified command 'new' is not a valid SDK command. Specify a valid SDK command. For more information, run dotnet help. Hopefully, the .NET team will fix that bug soon!Another type of help is command-line...

Practicing and exploring

Test your knowledge and understanding by answering some questions, getting some hands-on practice, and exploring with deeper research the topics in this chapter.

Exercise 1.1 – Online-only material

To preserve space in the print book, there are some optional online-only sections available in the GitHub repository. They are not needed for the rest of the book, but you will find them useful for general knowledge:

What’s New in Modern C# and .NET: In this section, the goal is to review what is new since C# 6 and .NET Core 1.0, which were released in 2016. Instead of just listing the new features introduced with each version of .NET, this section takes a themed approach to make it easier to understand how small individual improvements introduced over multiple versions are designed to work together. This section will be updated to cover .NET 11 in November 2026: https://github.com/markjprice/apps-services-net10/blob/main/docs/ch01-whats-new.md.
Benchmarking...

Summary

In this chapter, you:

Were introduced to the app and service technologies that you will learn about in this book.
Set up your development environment.
Learned where to look for help.

In the next chapter, you will learn how to use .NET MAUI to build cross-platform mobile apps.

Learn more on Discord

To join the Discord community for this book – where you can share feedback, ask questions to the author, and learn about new releases – follow the QR code below:

https://packt.link/apps_and_services_dotnet10