多線程18-QueueUserWorkItem

     class Proigram
    {
         private  static  void AsyncOperation( object state)
        {
            Console.WriteLine( " Operation state={0} ", state);
            Console.WriteLine( " work thread id={0} ", Thread.CurrentThread.ManagedThreadId);
            Thread.Sleep(TimeSpan.FromSeconds( 2));
        }
         static  void Main()
        {
             const  int x =  1;
             const  int y =  2;
             const  string lambdaState =  " lambda state 2 ";
            ThreadPool.QueueUserWorkItem(AsyncOperation);
            Thread.Sleep(TimeSpan.FromSeconds( 1));

            ThreadPool.QueueUserWorkItem(AsyncOperation, " saync state ");
            Thread.Sleep(TimeSpan.FromSeconds( 1));

            ThreadPool.QueueUserWorkItem(state => {
                Console.WriteLine( " Operation state :{0} ", state);
                Console.WriteLine( " ThreadId={0} ", Thread.CurrentThread.ManagedThreadId);
                Thread.Sleep( 5);
            }, " lambda state ");

            ThreadPool.QueueUserWorkItem(_ => {
                Console.WriteLine( " operation state:{0},{1} ", x + y, lambdaState);
                Console.WriteLine( " worker thread id :{0} ", Thread.CurrentThread.ManagedThreadId);
                Thread.Sleep( 4);
            }, " lambda state ");

            Thread.Sleep(TimeSpan.FromSeconds( 2));         }     }