Book Image

C# 9 and .NET 5 – Modern Cross-Platform Development - Fifth Edition

By : Mark J. Price
Book Image

C# 9 and .NET 5 – Modern Cross-Platform Development - Fifth Edition

By: Mark J. Price

Overview of this book

In C# 9 and .NET 5 – Modern Cross-Platform Development, Fifth Edition, expert teacher Mark J. Price gives you everything you need to start programming C# applications. This latest edition uses the popular Visual Studio Code editor to work across all major operating systems. It is fully updated and expanded with a new chapter on the Microsoft Blazor framework. The book’s first part teaches the fundamentals of C#, including object-oriented programming and new C# 9 features such as top-level programs, target-typed new object instantiation, and immutable types using the record keyword. Part 2 covers the .NET APIs, for performing tasks like managing and querying data, monitoring and improving performance, and working with the file system, async streams, serialization, and encryption. Part 3 provides examples of cross-platform apps you can build and deploy, such as websites and services using ASP.NET Core or mobile apps using Xamarin.Forms. The best type of application for learning the C# language constructs and many of the .NET libraries is one that does not distract with unnecessary application code. For that reason, the C# and .NET topics covered in Chapters 1 to 13 feature console applications. In Chapters 14 to 20, having mastered the basics of the language and libraries, you will build practical applications using ASP.NET Core, Model-View-Controller (MVC), and Blazor. By the end of the book, you will have acquired the understanding and skills you need to use C# 9 and .NET 5 to create websites, services, and mobile apps.
Table of Contents (23 chapters)

Understanding async and await

C# 5 introduced two keywords to simplify working with the Task type. They are especially useful for the following:

  • Implementing multitasking for a graphical user interface (GUI).
  • Improving the scalability of web applications and web services.

In Chapter 16, Building Websites Using the Model-View-Controller Pattern, we will see how the async and await keywords can improve scalability in websites.

In Chapter 21, Building Cross-Platform Mobile Apps, we will see how the async and await keywords can implement multitasking with a GUI.

But for now, let's learn the theory of why these two C# keywords were introduced, and then later you will see them used in practice.

Improving responsiveness for console apps

One of the limitations with console applications is that you can only use the await keyword inside methods that are marked as async but C# 7 and earlier do not allow the Main method to be marked as async! Luckily...