What this book covers

Chapter 1, Hello, C#! Welcome, .NET!, is about setting up your development environment and using either Visual Studio or Visual Studio Code to create the simplest application possible with C# and .NET. For simplified console apps, you will see the use of the top-level program feature introduced in C# 9. For learning how to write simple language constructs and library features, you will see the use of .NET Interactive Notebooks. You will also learn about some good places to look for help and ways to contact me to get help with an issue or give me feedback to improve the book and future editions through its GitHub repository.

Chapter 2, Speaking C#, introduces the versions of C# and has tables showing which versions introduced new features. I explain 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.

Chapter 3, Controlling Flow, Converting Types, and Handling Exceptions, covers using operators to perform simple actions on variables, including comparisons, writing code that makes decisions, pattern matching in C# 7 to C# 10, repeating a block of statements, and converting between types. It also covers writing code defensively to handle exceptions 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 about language features such as tuple syntax support and out variables, default literals, and inferred tuple names, as well as how to define and work with immutable types using the 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 member of a type, how to use polymorphism, how to create extension methods, how to cast between classes in an inheritance hierarchy, and about the big change in C# 8 with the introduction of nullable reference types.

Chapter 7, Packaging and Distributing .NET Types, introduces the versions of .NET and has tables showing which versions introduced new library features, and then presents .NET types that are compliant with .NET Standard and how they relate to C#. You will learn how to write and compile code on any of the supported operating systems: Windows, macOS, and Linux variants. You will learn how to package, deploy, and distribute 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, dates and times, storing items in collections, working with the network and manipulating images, and implementing internationalization.

Chapter 9, Working with Files, Streams, and Serialization, covers 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.

Chapter 10, Working with Data Using Entity Framework Core, explains reading and writing to relational databases, such as Microsoft SQL Server and SQLite, using the object-relational mapping (ORM) technology named Entity Framework Core (EF Core). You will learn how to define entity models that map to existing tables in a database, as well as how to define Code First models that can create the tables and database at runtime.

Chapter 11, Querying and Manipulating Data Using LINQ, teaches you about Language INtegrated Queries (LINQs)—language extensions that add the ability to work with sequences of items and filter, sort, and project them into different outputs. You will learn about the special capabilities of Parallel LINQ (PLINQ) and LINQ to XML.

Chapter 12, 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 13, 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 EF Core model to represent the Northwind database that will be used throughout the rest of the chapters in the book.

Chapter 14, 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 15, 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 16, 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 17, Building 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.

Three bonus online chapters complete this bumper edition. You can read the following chapters and the appendix at https://static.packt-cdn.com/downloads/9781801077361_Bonus_Content.pdf:

Chapter 18, Building and Consuming Specialized Services, introduces you to building services using gRPC, implementing real-time communications between server and client using SignalR, exposing an EF Core model using OData, and hosting functions in the cloud that respond to triggers using Azure Functions.

Chapter 19, Building Mobile and Desktop Apps Using .NET MAUI, introduces you to building cross-platform mobile and desktop apps for Android, iOS, macOS, and Windows. You will learn the basics of XAML, which can be used to define the user interface for a graphical app.

Chapter 20, 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.

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