关于Task类

private static void tt2()
        {
            Task task = null;
            for (int i = 0; i < 10; i++)
            {
                 task = Task.Factory.StartNew(callback, i);
            }
            Thread.Sleep(10000000);
        }
        private static void callback(object i)
        {
            Console.WriteLine("任务"+i.ToString()+"开始-执行");
            Thread.Sleep(10000);
            Console.WriteLine("任务" + i.ToString() + "结束");
        }

private static void tt3()
        {
            for (int i = 0; i < 10; i++)
            {
                Task task = new Task(callback, i);
                task.Start();
            }
            Thread.Sleep(10000000);
        }
        private static void callback(object i)
        {
            Console.WriteLine("任务"+i.ToString()+"开始-执行");
            Thread.Sleep(10000);
            Console.WriteLine("任务" + i.ToString() + "结束");
        }