using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            var t1 = GetTaskTestSum();      //
 
同步阻塞
            Console.WriteLine(t1.Result);

            var t2 = ToDoWithTimeOutAsync();    //同步阻塞
            Console.WriteLine(t2.Result);

            Console.ReadLine();
        }

        /// <summary>
        /// 測試
        /// </summary>
        /// <returns></returns>
        private
 
 static async Task<int> GetTaskTestSum()
        {
            int sum = 0;
            for (int i = 0; i <= 10; i++)
            {
                sum += 1;
                Console.WriteLine("sum += " + i);
                await Task.Delay(50);
            }

            return sum;
        }

        
 
private static async Task<string> ToDoAsync()
        {
            await Task.Delay(TimeSpan.FromSeconds(1));
            return "To Do Success";
        }

        private static async Task<string> ToTimeAsync()
        {
            await Task.Delay(2000);
            return "To Time Success";
        }

        /// <summary>
        /// Task.WhenAny任意一個任務完成返回
        /// </summary>
        /// <returns>返回String型別</returns>
        private static async Task<string> ToDoWithTimeOutAsync()
        {
            var toDoTaskAsync = ToDoAsync();
            var timeOutTaskAsync = ToTimeAsync();
            var msg = string.Empty;
            var completedTask = await Task.WhenAny(toDoTaskAsync, timeOutTaskAsync);
            return completedTask.Result;
        }
    }
}