Chapter 16, Asynchronous Programming

1. Task-based asynchronous pattern.
2. CancellationToken.
3. IProgress<T>.
4. An asynchronous method is declared, with the async keyword preceding the method name. The await keyword precedes an asynchronous operation and prevents the continuation of any further code until the asynchronous operation is complete. Task is what an asynchronous method returns. For void methods, the return type is Task, and for methods that return a value, the return type is Task<T>.
5. Create a new CancelationTokenSource and then set the method of cancelation, such as CancelAfter(3000).
6. Pass an IProgress<T> type into an asynchronous method as a parameter and add event handlers for the ProgressChanged event. Alternatively, you can pass a single handler into the Progress<T> constructor.