A Simple Example Practice in Async Programming

本文逻辑

介绍基本概念，实现一个小的Async Programming例子, 并对一些常用的概念作一些介绍

概念介绍

查看: [Programming IL] Delegates

实例逻辑

利用Delegate - BeginInvoke的两种调用方式进行编程

CallBack 回调式
Sequential 顺序执行

实例代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Remoting.Messaging;
  
namespace AsyncPatterns
{
    public class EventAsyncSample
    {
        private void OnCallBack(IAsyncResult result)
        {
            AsyncTargetCaller callback = (AsyncTargetCaller)((AsyncResult)result).AsyncDelegate;
  
            Int64 number = (int)result.AsyncState;
            number = callback.EndInvoke(result);
  
            Console.WriteLine("The Result Is: {0}", number);
        }
  
        /// <summary>
        /// Call the target and invoke a method outside when done
        /// </summary>
  
        public void AsyncCallTarget()
        {
            AsyncTargetCaller caller = new AsyncTargetCaller(AsyncTarget.Sum);
  
            AsyncCallback callback = new AsyncCallback(OnCallBack);
            int number = int.MaxValue;
            caller.BeginInvoke(number, callback, number);
  
            Console.WriteLine("Begin To Call the AsyncTarget");
        }
  
        /// <summary>
        /// No Callback, get all done in a single method
        /// </summary>
  
        public void WaitAsyncCallTarget()
        {
            AsyncTargetCaller caller = new AsyncTargetCaller(AsyncTarget.Sum);
            IAsyncResult result = caller.BeginInvoke(int.MaxValue, null, null);
  
            while (!result.IsCompleted)
            {
                result.AsyncWaitHandle.WaitOne(1000);
                Console.WriteLine("Waiting for you");
            }
  
            Console.WriteLine("WaitAsyncCallTarget Result: {0}", caller.EndInvoke(result));
        }
    }
  
    /// <summary>
    /// The target to be called
    /// </summary>
    public class AsyncTarget
    {
        public static Int64 Sum(Int32 number)
        {
            Console.WriteLine("Entering the Sum UpdateMilestone");
            Int64 m_Temp = 0;
            for (int i = number; i > 0; i--)
            {
                m_Temp += i;
            }
            return m_Temp;
        }
    }
  
    /// <summary>
    /// A delegatet to call the method
    /// </summary>
    /// <param name="number"></param>
    /// <returns></returns>
    public delegate Int64 AsyncTargetCaller(int number);
  
}