Professional C# 7 and .NET Core 2.0, 7th Edition

15Asynchronous Programming

WHAT’S IN THIS CHAPTER?

• The importance of asynchronous programming
• Asynchronous patterns
• Foundations of asynchronous programming
• Error handling with asynchronous methods
• Asynchronous programming with Windows Apps

WROX.COM CODE DOWNLOADS FOR THIS CHAPTER

The Wrox.com code downloads for this chapter are found at www.wrox.com on the Download Code tab. The source code is also available at https://github.com/ProfessionalCSharp/ProfessionalCSharp7 in the directory Async.

The code for this chapter is divided into the following major examples:

• AsyncHistory
• Foundations
• Error Handling
• AsyncWindowsApp

WHY ASYNCHRONOUS PROGRAMMING IS IMPORTANT

The .NET Framework 4.5 added the Task Parallel Library (TPL) to .NET to make parallel programming easier. C# 5.0 added two keywords to make asynchronous programming easier: async and await. These two keywords are the main focus of this chapter.

With asynchronous programming a method is called that runs in the background (typically with the help of a thread or task), and the calling thread is not blocked.

In this chapter, you can read about different patterns on asynchronous programming such as the asynchronous pattern, the event-based asynchronous pattern, and the task-based asynchronous pattern (TAP). TAP makes use of the async and await keywords. When you compare these patterns, you can see the real advantage of this style of asynchronous programming.

After discussing the different patterns, you see the ...