Canceling asynchronous operations

In this section, we will look at how we can cancel long-running asynchronous operations. Sometimes a task will take longer than it should do. A good example of this is fetching data from a website when it goes down. Asynchronous operations can take a long time before they are reset by the server due to something like Error 404, Error 401, or Error 500 for example. And so, it pays to have the ability to cancel an asynchronous operation after a set period to prevent wasting an end user's time.

The code we will write will return the text from a website URL. We will assign a very short timeout. This timeout will cancel the task that is responsible for returning the website text. Follow these steps:

1. Open the CH16_AsynchronousProgramming project, and add a new class called TaskCancellation.
2. Add the using System.Text; statement.
3. Add the following two member variables:

   private const string _website = 
       "https...