多线程17-Async Programming Model

    class Program
    {
        private delegate string RunOnThreadPool(out int threadId);
        private static void Callback(IAsyncResult ar)
        {
            Console.WriteLine("Starting a callback");
            Console.WriteLine("State passed to a callback:{0}", ar.AsyncState);
            Console.WriteLine("Is Thread Polll Thread={0}", Thread.CurrentThread.IsThreadPoolThread);
            Console.WriteLine("Thread pool worker thread id :{0}", Thread.CurrentThread.ManagedThreadId);
        }
        private static string Test(out int ThreadId)
        {
            Console.WriteLine("Starting ....");
            Console.WriteLine("Is thread pool thread:{0}", Thread.CurrentThread.IsThreadPoolThread);
            Thread.Sleep(2);
            ThreadId = Thread.CurrentThread.ManagedThreadId;
            return string.Format("Thread pool worker therad id was ={0}", ThreadId);
        }
        static void Main()
        {
            int threadId = 0;
            RunOnThreadPool poolDelegate = Test;
            var t = new Thread(() => Test(out threadId));
            t.Start();
            t.Join();
            Console.WriteLine("Thread id:{0}", threadId);
            IAsyncResult r = poolDelegate.BeginInvoke(out threadId, Callback, "a delegae asyncResult call");
            string result = poolDelegate.EndInvoke(out threadId, r);
            Console.WriteLine("Thread pool worker thread id:{0}", threadId);
            Console.WriteLine(result);
            Thread.Sleep(TimeSpan.FromSeconds(2));
        }
    }