使用AsyncCallback处理异步调用

using System.Threading;
using System;
using System.Runtime.Remoting.Messaging; //不要忘记该引用，AsyncResult（异布调用的结果）

namespace SyncDelegate
{
public delegate int BinaryOp(int x, int y);

class Program
{
static void Main(string[] args)
{
Console.WriteLine("***** Synch Delegate Review *****");

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"); //使用AsyncCallback实现异步回调:引用在异步操作完成时调用的回调方法。
Console.ReadLine();

}

static void AddComplete(IAsyncResult itfAR)//异步操作完成时执行的方法
{
Console.WriteLine("AddComplete() invoked on thread {0}", Thread.CurrentThread.ManagedThreadId);
Console.WriteLine("addition is complete");

AsyncResult ar = (AsyncResult)itfAR; //AsyncResult封装对委托的异步操作的结果
BinaryOp b = (BinaryOp)ar.AsyncDelegate;//AsyncDelegate获取原委托对象
Console.WriteLine("10+10 is {0}", b.EndInvoke(itfAR));

string msg = (string)itfAR.AsyncState;//AsyncState获取主线程传入的数据
Console.WriteLine(msg);

}

#region Very time consuming addition!
static int Add(int x, int y)
{
Console.WriteLine("Add() invoked on thread {0}.",
Thread.CurrentThread.ManagedThreadId);

Thread.Sleep(3000);
return x + y;
}
#endregion
}
}