.net 4.5 新特性 async await 一般处理程序实例

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Web;

namespace PaoTui.ServerSide.WeChat
{
/// <summary>
/// AsyncHandler1 的摘要说明
/// </summary>
public class AsyncHandler1 : IHttpHandler
{

public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/html";
if (context.Request.QueryString["para"] == "1")
{
context.Response.Write("主方法开始<br/>");
//Task<int> result = GetIntResult(context); 带参数 方法
GetIntResult(context);//不带参数方法
context.Response.Write(" 主方法开始画圈圈<br/>");
for (int i = 0; i < 100; i++)
{
context.Response.Write("○");
}
context.Response.Write("
 主方法画圈圈结束<br/>");
context.Response.Write("开始判断异步方法是否完成<br/>");
//if (!result.IsCompleted)
//{
// context.Response.Write("异步方法未完成,开始等待<br/>");
// result.Wait();
//}
//else
//{
// context.Response.Write("异步方法为完成<br/>");
//}
//context.Response.Write(" 最终结果:" + result.Result);
context.Response.Write("<br/>主方法结束");
}
else
{

context.Response.Write(" 同步方法开始,开始计算0到2的和<br/>");

int r = 0;
for (int i = 0; i < 5; i++)
{
r += i;
Thread.Sleep(1000);
}
context.Response.Write(" 主方法开始画圈圈<br/>");
for (int i = 0; i < 100; i++)
{
context.Response.Write("○");
}
context.Response.Write("<br/>主方法结束");
}

}

public bool IsReusable
{
get
{
return false;
}
}
///带参数返回方法
//public async Task<int> GetIntResult(HttpContext context)
//{

// context.Response.Write(" 异步方法开始调用<br/>");
// int result = await Task<int>.Run<int>(() =>
// {
// context.Response.Write(" await异步操作开始,开始计算0到2的和<br/>");
// int r = 0;
// for (int i = 0; i < 2; i++)
// {
// r += i;
// Thread.Sleep(1000);
// }
// context.Response.Write(" await异步操作结束<br/>");
// return r;
// });
// context.Response.Write(" 异步方法调用结束<br/>");
// return result;
//}
/// <summary>
/// 不带参数返回方法
/// </summary>
/// <param name="context"></param>
public async void GetIntResult(HttpContext context)
{

context.Response.Write(" 异步方法开始调用<br/>");
await Task.Run(() =>
{
context.Response.Write(" await异步操作开始,开始计算0到2的和<br/>");
int r = 0;
for (int i = 0; i < 5; i++)
{
r += i;
Thread.Sleep(1000);
}
context.Response.Write(" await异步操作结束<br/>" + r);

});
//context.Response.Write(" 异步方法调用结束<br/>" + r);

}
}
}