jquery, json与ashx的完美结合

AJAX的应用程序，免不了经常需要在页面和服务之间异步传输数据。我已经多次写过这方面的东西。下面还是有一个比较经典的案例，我认为掌握到这些，那么处理异步请求的时候就相当方便了。
 
第一部分：客户端页面

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm3.aspx.cs" Inherits="WebApplication1.WebForm3" %>








"json2.js" type="text/javascript">

"text/javascript">
$(function() {
//构造一个json对象，很类似于C#中的匿名类型
var employee = {
Name: "chenxizhang",
Country: "China",
Orders: [
{ OrderID: 10248 },
{ OrderID: 10249 }
]
};

//发送POST请求，数据也是json格式。但数值部分需要转换为字符串
$.post("EmployeeHandler.ashx", { data: JSON.stringify(employee) }, function(result) {
var r = JSON.parse(result);
alert(r.Message);
});
});

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

第二部分：ashx部分

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Runtime.Serialization.Json;
using System.Runtime.Serialization;
using System.IO;
using System.Text;
//必须添加System.ServiceModel.Web和System.Runtime.Serialization的引用
namespace WebApplication1
{
///
/// $codebehindclassname$ 的摘要说明
///
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class EmployeeHandler : IHttpHandler
{

public void ProcessRequest(HttpContext context)
{
var ser = new DataContractJsonSerializer(typeof(Employee));
var data = context.Request["data"];
var ms = new MemoryStream(Encoding.UTF8.GetBytes(data));
var emp = (Employee)ser.ReadObject(ms);
ms.Close();
//此时已经得到了相应的Employee实例，可以进行服务器端的处理

var ser2 = new DataContractJsonSerializer(typeof(ActionResult));
var ms2 = new MemoryStream();
var result = new ActionResult() { Code = 200, Message = "成功" };
ser2.WriteObject(ms2, result);
ms2.Position = 0;
var buffer = new byte[ms2.Length];
ms2.Read(buffer, 0, buffer.Length);
ms2.Close();
context.Response.Write(Encoding.UTF8.GetString(buffer));

//返回结果

}

public bool IsReusable
{
get
{
return false;
}
}
}

[DataContract]
public class Employee {
[DataMember]
public string Name { get; set; }

[DataMember]
public string Country { get; set; }

[DataMember]
public OrderItem[] Orders { get; set; }

}
[DataContract]
public class OrderItem
{
[DataMember]
public int OrderID { get; set; }
}

[DataContract]
public class ActionResult
{
[DataMember]
public int Code { get; set; }
[DataMember]
public string Message { get; set; }

}
}

第三部分：进一步的优化，编写两个扩展方法（这是C# 3.0的新特性）

///
/// 这个类型实现了对JSON数据处理的一些扩展方法
///
public static class JsonExtensions
{
///
/// 根据一个字符串，进行JSON的反序列化，转换为一个特定类型
///
///
///
///
public static T ToJsonObject(this string data) {
var serializer = new DataContractJsonSerializer(typeof(T));
var ms = new MemoryStream(
Encoding.UTF8.GetBytes(data));

var result = (T)serializer.ReadObject(ms);
ms.Close();
return result;
}
///
/// 将任何一个对象转换为JSON字符串
///
///
///
///
public static string ToJsonString(this T obj) {
var serializer = new DataContractJsonSerializer(typeof(T));
var ms = new MemoryStream();
serializer.WriteObject(ms, obj);
ms.Position = 0;
var result = Encoding.UTF8.GetString(ms.GetBuffer());
ms.Close();
return result;
}
}

这样，在ashx里面的代码就很简单了

var emp = context.Request["data"].ToJsonObject();
var result = new ActionResult() { Code = 200, Message = "成功" };
context.Response.Write(result.ToJsonString());

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

不错吧，这样以后处理Json就是如此容易

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

通过Json来传递数据，可以避免以前用传统的post或者get方面拼接字符串中的麻烦