C #, Thread, Task, Async / Await, IAsyncResult of those things! (Reprint)

reference

Asynchronous execution

  static  void the Main ( String [] args) 
        {          
            Console.WriteLine ( " ------- main thread start ------- " ); 
            the Task < int > = Task GetStrLengthAsync (); 
            Console.WriteLine ( " the main thread to continue " ); 
            Console.WriteLine ( " Task return value " + task.Result); 
            Console.WriteLine ( " ------- main thread ends ------- " ); 
            Console. ReadKey (); 
        } 
        static  the async the Task <int > GetStrLengthAsync () 
        { 
            Console.WriteLine ( " GetStrLengthAsync method to begin " );
             // string type returned here <string> is, instead of the Task <string> 
            String STR = the await the GetString (); 
            Console.WriteLine ( " GetStrLengthAsync method has finished executing " );
             return str.length; 
        } 

        static the Task < String > the GetString () 
        { 
            // Console.WriteLine ( "begin the GetString method") 
            return the Task < String > .Run (() =>
            { 
                The Thread.Sleep ( 2000 ); 
                Console.WriteLine ( " the GetString return value " );
                 return  " the GetString return value " ; 
            }); 
        }

 

2 Comparison with asynchronous callback

asynchronous

 static void Main(string[] args)
        {          
            for (int i = 0; i < 100; i++)
            {
                test(i);
            }
            Console.ReadKey();
        }

        static private void test(int i)
        {
            Task<int> task = GetStrLengthAsync(i);
        }
        static async Task<int> GetStrLengthAsync(int i)
        {
            Console.WriteLine(i);
            string str = await GetString(i);
            Console.WriteLine($"结束{i}");
            return str.Length;
          
        }

        static Task<string> GetString(int i)
        {
            //Console.WriteLine("GetString方法开始执行")
            return Task<string>.Run(() =>
            {
                Thread.Sleep(10000);
                Console.WriteLine($"耗时操作{i}");
                return " The GetString return value " ; 
            }); 
        }

Callback

         private delegate void AddHandler(int i);
        static void Main(string[] args)
        {          
            for (int i = 0; i < 100; i++)
            {
                test2(i);
            }
            Console.ReadKey();
        }
      
        static private void test2(int i)
        {
            AddHandler addHandler = new AddHandler(test3);
            addHandler.BeginInvoke(i,null,null);
        } 
        static private void test3(int i)
        {
            Console.WriteLine(i);
            test4(i);
            Console.WriteLine($"结束{i}");
        }
        static private void test4(int i)
        {
            Thread.Sleep(10000);
            Console.WriteLine($"耗时操作{i}");
        }