What this book covers

Chapter 1, Hello, C#! Welcome, .NET!, is about setting up your development environment and using Visual Studio Code to create the simplest application possible with C# and .NET. You will learn how to write and compile code on any of the supported operating systems: Windows, macOS, and Linux variants. For simplified console apps, you will see the use of the top-level program feature introduced in C# 9. You will also learn the best places to look for help.

Chapter 2, Speaking C#, introduces the versions of C# and has tables showing which version introduced new features, and then explains the grammar and vocabulary that you will use every day to write the source code for your applications. In particular, you will learn how to declare and work with variables of different types, and about the big change in C# 8 with the introduction of nullable reference types.

Chapter 3, Controlling Flow and Converting Types, covers using operators to perform simple actions on variables including comparisons, writing code that makes decisions, pattern matching in C# 7 to C# 9, repeating a block of statements, and converting between types. It also covers writing code defensively to handle errors when they inevitably occur.

Chapter 4, Writing, Debugging, and Testing Functions, is about following the Don't Repeat Yourself (DRY) principle by writing reusable functions using both imperative and functional implementation styles. You will also learn how to use debugging tools to track down and remove bugs, monitoring your code while it executes to diagnose problems, and rigorously testing your code to remove bugs and ensure stability and reliability before it gets deployed into production.

Chapter 5, Building Your Own Types with Object-Oriented Programming, discusses all the different categories of members that a type can have, including fields to store data and methods to perform actions. You will use object-oriented programming (OOP) concepts, such as aggregation and encapsulation. You will learn language features such as tuple syntax support and out variables, and default literals and inferred tuple names, as well as how to define and work with immutable types using the new record keyword, init-only properties, and with expressions introduced in C# 9.

Chapter 6, Implementing Interfaces and Inheriting Classes, explains deriving new types from existing ones using OOP. You will learn how to define operators and local functions, delegates and events, how to implement interfaces about base and derived classes, how to override a type member, how to use polymorphism, how to create extension methods, and how to cast between classes in an inheritance hierarchy.

Chapter 7, Understanding and Packaging .NET Types, introduces the versions of .NET and has tables showing which version introduced new features, and then presents .NET types that are compliant with .NET Standard, and how they relate to C#. You will learn how to deploy and package your own apps and libraries.

Chapter 8, Working with Common .NET Types, discusses the types that allow your code to perform common practical tasks, such as manipulating numbers and text, storing items in collections, and implementing internationalization.

Chapter 9, Working with Files, Streams, and Serialization, talks about interacting with the filesystem, reading and writing to files and streams, text encoding, and serialization formats like JSON and XML, including the improved functionality and performance of the System.Text.Json classes in .NET 5.

Chapter 10, Protecting Your Data and Applications, is about protecting your data from being viewed by malicious users using encryption, and from being manipulated or corrupted using hashing and signing. You will also learn about authentication and authorization to protect applications from unauthorized users.

Chapter 11, Working with Databases Using Entity Framework Core, explains reading and writing to databases, such as Microsoft SQL Server and SQLite, using the object-relational mapping (ORM) technology named Entity Framework Core.

Chapter 12, Querying and Manipulating Data Using LINQ, teaches you Language INtegrated Queries (LINQ)—language extensions that add the ability to work with sequences of items and filter, sort, and project them into different outputs.

Chapter 13, Improving Performance and Scalability Using Multitasking, discusses allowing multiple actions to occur at the same time to improve performance, scalability, and user productivity. You will learn about the async Main feature and how to use types in the System.Diagnostics namespace to monitor your code to measure performance and efficiency.

Chapter 14, Introducing Practical Applications of C# and .NET, introduces you to the types of cross-platform applications that can be built using C# and .NET. You will also build an entity model to represent the Northwind database that will be used throughout Chapters 15 to 21.

Chapter 15, Building Websites Using ASP.NET Core Razor Pages, is about learning the basics of building websites with a modern HTTP architecture on the server side using ASP.NET Core. You will learn how to implement the ASP.NET Core feature known as Razor Pages, which simplifies creating dynamic web pages for small websites, and about building the HTTP request and response pipeline.

Chapter 16, Building Websites Using the Model-View-Controller Pattern, is about learning how to build large, complex websites in a way that is easy to unit test and manage with teams of programmers using ASP.NET Core MVC. You will learn about startup configuration, authentication, routes, models, views, and controllers.

Chapter 17, Building Websites Using a Content Management System, explains how a web Content Management System (CMS) can enable developers to rapidly build websites with a customizable administration user interface that non-technical users can use to create and manage their own content. As an example, you will learn about a simple open source .NET-based one named Piranha CMS.

Chapter 18, Building and Consuming Web Services, explains building backend REST architecture web services using the ASP.NET Core Web API and how to properly consume them using factory-instantiated HTTP clients.

Chapter 19, Building Intelligent Apps Using Machine Learning, introduces you to Microsoft's open source ML.NET package of machine learning algorithms, which can be used to embed adaptive intelligence into any cross-platform .NET app, such as a digital commerce website that provides product recommendations for visitors to add to their shopping cart.

Chapter 20, Building Web User Interfaces Using Blazor, introduces how to build web user interface components using Blazor that can be executed either on the server side or inside the client-side web browser. You will see the differences between Blazor Server and Blazor WebAssembly and how to build components that are easier to switch between the two hosting models.

Chapter 21, Building Cross-Platform Mobile Apps, introduces you to taking C# mobile by building a cross-platform app for iOS and Android. The app for this chapter will be built using Visual Studio 2019 for Mac on macOS.

Appendix A, Answers to the Test Your Knowledge Questions, has the answers to the test questions at the end of each chapter.

Appendix B, Building Windows Desktop Apps, introduces you to how .NET 5 and its Windows Desktop Pack enable Windows Forms and WPF apps to benefit from running on .NET 5. You will then learn the basics of XAML, which can be used to define the user interface for a graphical app for Windows Presentation Foundation (WPF) or the Universal Windows Platform (UWP). You will apply the principles and features of Fluent Design to light up a UWP app. The apps for this chapter must be built using Visual Studio 2019 on Windows 10.

You can read both appendices at the following link: https://static.packt-cdn.com/downloads/9781800568105_Appendices.pdf.