Book Image

C# 8.0 and .NET Core 3.0 – Modern Cross-Platform Development - Fourth Edition

By : Mark J. Price
Book Image

C# 8.0 and .NET Core 3.0 – Modern Cross-Platform Development - Fourth Edition

By: Mark J. Price

Overview of this book

In C# 8.0 and .NET Core 3.0 – Modern Cross-Platform Development, Fourth 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 new chapters on Content Management Systems (CMS) and machine learning with ML.NET. The book covers all the topics you need. Part 1 teaches the fundamentals of C#, including object-oriented programming, and new C# 8.0 features such as nullable reference types, simplified switch pattern matching, and default interface methods. Part 2 covers the .NET Standard APIs, such as managing and querying data, monitoring and improving performance, working with the filesystem, async streams, serialization, and encryption. Part 3 provides examples of cross-platform applications you can build and deploy, such as web apps using ASP.NET Core or mobile apps using Xamarin.Forms. The book introduces three technologies for building Windows desktop applications including Windows Forms, Windows Presentation Foundation (WPF), and Universal Windows Platform (UWP) apps, as well as web applications, web services, and mobile apps.
Table of Contents (21 chapters)

Raising and handling events

Methods are often described as actions that an object can perform, either on itself or to related objects. For example, List can add an item to itself or clear itself, and File can create or delete a file in the filesystem.

Events are often described as actions that happen to an object. For example, in a user interface, Button has a Click event, click being something that happens to a button. Another way of thinking of events is that they provide a way of exchanging messages between two objects.

Events are built on delegates, so let's start by having a look at how delegates work.

Calling methods using delegates

You have already seen the most common way to call or execute a method: use the . operator to access the method using its name. For example, Console.WriteLine tells the Console type to access its WriteLine method.

The other way to call or execute a method is to use a delegate. If you have used languages that support function pointers...