证明task线程是来源于线程池的，线程重用

namespace task_threadpool
{
    class Program
    {
        static void Main(string[] args)
        {
            ThreadPool.SetMaxThreads(5, 5);
            for (int i = 0; i < 100; i++)
            {
                int k = i;
                Task.Run(() =>
                {
                    Console.WriteLine($"This is {k} running ThreadId={Thread.CurrentThread.ManagedThreadId.ToString("00")}");
                    Thread.Sleep(2000);
                });
            }
            Console.Read();
        }
    }
}