AsynCallback 委托异步调用

using System;

using System.Collections.Generic;

using System.Text;

using System.Threading;

using System.Runtime.Remoting.Messaging;

namespace AsyncCallbackDelegate

{

  public delegate int BinaryOp(int x, int y);

  class Program

  {

    static void Main(string[] args)

    {

      Console.WriteLine("*****  AsyncCallbackDelegate Example *****");

      Console.WriteLine("Main() invoked on thread {0}.",

        Thread.CurrentThread.ManagedThreadId);

      BinaryOp b = new BinaryOp(Add);

      IAsyncResult iftAR = b.BeginInvoke(10, 10, new AsyncCallback(AddComplete), "Main() thanks you for adding these numbers.");

      // Assume other work is performed here...

      Console.ReadLine();

    }

    #region Target for AsyncCallback delegate

    // Don't forget to add a 'using' directive for

    // System.Runtime.Remoting.Messaging!

    static void AddComplete(IAsyncResult itfAR)

    {

      Console.WriteLine("AddComplete() invoked on thread {0}.",

        Thread.CurrentThread.ManagedThreadId);

      Console.WriteLine("Your addition is complete");

      // Now get the result.

      AsyncResult ar = (AsyncResult)itfAR;

      BinaryOp b = (BinaryOp)ar.AsyncDelegate;

      Console.WriteLine("10 + 10 is {0}.", b.EndInvoke(itfAR));

      // Retrieve the informational object and cast it to string

      string msg = (string)itfAR.AsyncState;

      Console.WriteLine(msg);

    }

    #endregion

    #region Target for BinaryOp delegate

    static int Add(int x, int y)

    {

      Console.WriteLine("Add() invoked on thread {0}.",

        Thread.CurrentThread.ManagedThreadId);

      Thread.Sleep(5000);

      return x + y;

    }

    #endregion

  }

}