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)
22
Index

Understanding SignalR

In the early days of the Web in the 1990s, browsers had to make a full-page HTTP GET request to the web server to get fresh information to show to the visitor.

In late 1999, Microsoft released Internet Explorer 5.0 with a component named XMLHttpRequest that could make asynchronous HTTP calls in the background. This alongside dynamic HTML (DHTML) allowed parts of the web page to be updated with fresh data smoothly.

The benefits of this technique were obvious and soon all browsers added the same component. Google took maximum advantage of this capability to build clever web applications such as Google Maps and Gmail. A few years later, the technique became popularly known as Asynchronous JavaScript and XML (AJAX).

AJAX still uses HTTP to communicate, however, and that has limitations. First, HTTP is a request-response communication protocol, meaning that the server cannot push data to the client. It must wait for the client to make a request. Second...