c# Task.FromResult 的基本用法和实例

This method is useful when you perform an asynchronous operation that returns a Task object, and the result of that Task object is already computed

There are two common use cases I've found:

When you're implementing an interface that allows asynchronous callers, but your implementation is synchronous.
When you're stubbing/mocking asynchronous code for testing

上面总体来说是用于单元测试；

然后还有在我们读取缓存的时候有用；微软官方博客实例；

https://docs.microsoft.com/en-us/dotnet/standard/parallel-programming/how-to-create-pre-computed-tasks

上面的思想：

This method is useful when you perform an asynchronous operation that returns a Task object, and the result of that Task object is already computed.

已经计算出来了，或者已经缓存好了，基本想要的值；

这里添加一个基本的链接功能：

那就是我们的异步方法中的进度报告的问题；https://social.technet.microsoft.com/wiki/contents/articles/19020.progress-of-a-task-in-c.aspx

效果是非常好的呀；