2.1. Pausing for a Period of Time
Problem
You need to (asynchronously) wait for a period of time. This can be useful when unit testing or implementing retry delays. This solution can also be useful for simple timeouts.
Solution
The Task type has a static method Delay that returns a task that completes after the specified time.

2.2. Returning Completed Tasks
Problem
You need to implement a synchronous method with an asynchronous signature. This situation can arise if you are inheriting from an asynchronous interface or base class but wish to implement it synchronously. This technique is particularly useful when unit testing asynchronous code, when you need a simple stub or mock for an asynchronous interface.
Solution
You can use Task.FromResult to create and return a new Task<T> that is already completed with the specified value:

2.3. Reporting Progress
Problem
You need to respond to progress while an asynchronous operation is executing.
Solution
Use the provided IProgress<T> and Progress<T> types. Your async method should take an IProgress<T> argument; the T is whatever type of progress you need to report:

2.3. Reporting Progress
Problem
You need to respond to progress while an asynchronous operation is executing.
Solution
Use the provided IProgress<T> and Progress<T> types. Your async method should take an IProgress<T> argument; the T is whatever type of progress you need to report: