About async await the test

async await tutorial: https://www.cnblogs.com/zhaoshujie/p/11192036.html

 

Asynchronous methods:

        private async Task<string> TestAsync()
        {
            Console.WriteLine ( " Asynchronous method begins " );
             var Task Task.Run = (() =>
            {
                Thread.Sleep(2000);
                Console.WriteLine ( " new thread " );
                 return  " new thread end " ;
            });

            var result = await task;
            Console.WriteLine ( " Asynchronous method ends " );

            return result;
        }

When not in use await call

        public IActionResult Index()
        {
            Console.WriteLine ( " main thread start " );
            Console.WriteLine ( " output: " + TestAsync ());
            Console.WriteLine ( " main thread end " );
        }

result:

1, the main thread ++ code prior to await the asynchronous method executed in the order

2, await the start (open a new thread)

Get value TestAsync (); a: 3, the main thread remaining code execution, Console.WriteLine (+ TestAsync () "output")

4, await the end, the code continues await asynchronous method

---

 Use await when calling

        public async Task<IActionResult> Index()
        {
            Console.WriteLine ( " main thread start " );
            Console.WriteLine ( " output: " + the await TestAsync ());
            Console.WriteLine ( " main thread end " );
        }

result:

All the execution order, return can get the correct value