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

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            List<Task> taskList = new List<Task>();
            taskList.Add( Task.Factory.StartNew(()=> {
                Thread.Sleep(1000);
                Console.WriteLine("1秒執行結束");
            }));
            taskList.Add(Task.Factory.StartNew(() => {
                Thread.Sleep(800);
                Console.WriteLine("o.8秒執行結束");
            }));
            Console.WriteLine("執行中");
            TaskFactory taskFactory = new TaskFactory();
            taskList.Add(taskFactory.ContinueWhenAll(taskList.ToArray(), tArray =>
            { Thread.Sleep(200); Console.WriteLine("等待這些完成後執行"); }));
            //Console.WriteLine("執行完成");

            Console.Read();

        }
    }
}

C# 使用TASK處理多任務同時處理