using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading; //异步调用
//IAsyncResult BeginInvoke(argument,AsyncCallback callback,object asynState)
//argument - 如果没有参数，callback就是第一个参数
//BeginInvoke返回值是IAsyncResult
//AsyncState - 传递给异步调用的那个状态对象
//AsyncWaitHandle - 在异步操作完成前，一直使用WaitHandle阻断调用线程
//CompleteSynchronously - 指示一步操作是否同步完成
//IsCompleted - 指示异步操作已经完成 namespace Starter
{
public delegate void DeleageteClass(); class Program
{
static void Main(string[] args)
{
DeleageteClass del = MethodA; DelegateStateBag state = new DelegateStateBag(); IAsyncResult ar = del.BeginInvoke(Callback,state); if (ar.IsCompleted == true)
{
Console.WriteLine("MethodA completed");
}
else
{
Console.WriteLine("MethodA not completed");
} ar.AsyncWaitHandle.WaitOne(); //do something else //Sleep - 不然会产生竞争，同时启动Callback和main，Sleep是消除竞争的根本办法
Thread.Sleep(100); lock (state)
{
Console.WriteLine("Back in main");
Console.WriteLine(state.message);
} Console.ReadLine();
} public static void Callback(IAsyncResult ar)
{
DelegateStateBag state = (DelegateStateBag)ar.AsyncState ;
lock(state)
{
Console.WriteLine("Call back running");
((DelegateStateBag)ar.AsyncState).message =
"State object modify in callack";
} } public static void MethodA()
{
Console.WriteLine("MethodA running....");
Thread.Sleep(200);
}
} class DelegateStateBag
{
public string message;
}
}