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)

Debugging during development

In this section, you will learn how to debug problems at development time.

Creating code with a deliberate bug

Let's explore debugging by creating a console app with a deliberate bug that we will then use the tools to track down and fix.

  1. In Chapter04, create a folder named Debugging, add it to the workspace, and create a console application in the folder.
  2. Navigate to View | Command Palette, enter and select OmniSharp: Select Project, and then select the Debugging project.
  3. In the Debugging folder, open and modify Program.cs to define a function with a deliberate bug and call it in the Main method, as shown in the following code:
    using static System.Console;
    namespace Debugging
      class Program
        static double Add(double a, double b)
          return a * b; // deliberate bug!
        static void Main(string[] args)
          double a = 4.5; // or use var
          double b = 2.5;
          double answer = Add(a, b);