Code
summary 在不同的 .NET 版本中返回 JSON
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简介/目录
请到 下载资源 的 JQueryElement 示例下载一节*下载示例代码, 目录 /returnjson/Default.aspx.
视频演示: www.tudou.com/programs/view/rHCYHX9cmcI/
本文将说明如何通过一般处理程序 ashx 和 WebService 来向客户端 javascript 返回 JSON:
- 准备
- 一般处理程序/ashx
- WebService/asmx
准备
如果希望通过 ashx 或者 asmx 来返回 JSON, 那么*需要引用程序集 System.Web.Extensions.dll, 在 .NET 3.5, 4.0 中已经默认包含. 对于 .NET 2.0, 3.0, 需要安装 ASP.NET 2.0 AJAX, 可以在 www.microsoft.com/download/en/details.aspx?displaylang=en&id=883 下载.
一般处理程序/ashx
使用一般处理程序返回 JSON, 对于不同版本的 .NET 都是类似, 请看下面的 handler.ashx 的代码:
上面的例子中, 通过 JavaScriptSerializer 类的 Serialize 方法, 将对象转化为 JSON 对应的字符串. 而转化的对象是 SortedDictionary, 会生成<%@ WebHandler Language="C#" Class="handler" %>
using System;
using System.Web;
using System.Web.Script.Serialization;
using System.Collections.Generic;
public class handler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/javascript";
context.Response.Cache.SetNoStore ( );
string name = context.Request["name"];
SortedDictionary<string, object> values = new SortedDictionary<string, object>();
values.Add("message",
string.IsNullOrEmpty(name) ? "无名氏" :
string.Format("你好 {0}, {1}", name, DateTime.Now));
context.Response.Write(new JavaScriptSerializer().Serialize(values));
}
public bool IsReusable
{
get { return false; }
}
}
{ "message": "你好 x, 20xx-xx-xx xx:xx:xx" }这样类似的字符串. 如果需要返回数组, 可以定义 object.md 来转换. 代码中还使用了context.Response.Cache.SetNoStore ( );来让浏览器每次请求 ashx 时都重新访问, 而不是使用缓存.
如果使用 jQuery, 可以使用下面的函数来接收 JSON:
function(data){
alert(data.message);
}
WebService/asmx
在不同版本的 .NET 中, 通过 javascript 访问 WebService 并返回 JSON 是略有不同的. 首先, 可以分别采用不同的 Web.config 文件.
.NET 2.0, 3.0 Web.config<?xml version="1.0"?>
<configuration>
<system.web>
<compilation debug="true">
<assemblies>
<add
assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</assemblies>
</compilation>
<pages/>
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx"
type="System.Web.Script.Services.ScriptHandlerFactory"
validate="false"/>
</httpHandlers>
</system.web>
</configuration>
.NET 3.5 Web.config<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
<sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/>
<section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
<section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
</sectionGroup>
</sectionGroup>
</sectionGroup>
</configSections>
<system.web>
<compilation debug="true">
<assemblies>
<add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
<add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
<add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
</assemblies>
</compilation>
<pages>
<controls>
<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</controls>
</pages>
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" validate="false" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</httpHandlers>
<httpModules>
<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</httpModules>
</system.web>
<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" warningLevel="4">
<providerOption name="CompilerVersion" value="v3.5"/>
<providerOption name="WarnAsError" value="false"/>
</compiler>
<compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.VisualBasic.VBCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" warningLevel="4">
<providerOption name="CompilerVersion" value="v3.5"/>
<providerOption name="OptionInfer" value="true"/>
<providerOption name="WarnAsError" value="false"/>
</compiler>
</compilers>
</system.codedom>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<modules>
<remove name="ScriptModule"/>
<add name="ScriptModule" preCondition="managedHandler" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</modules>
<handlers>
<remove name="WebServiceHandlerFactory-Integrated"/>
<remove name="ScriptHandlerFactory"/>
<remove name="ScriptHandlerFactoryAppServices"/>
<remove name="ScriptResource"/>
<add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add name="ScriptResource" verb="GET,HEAD" path="ScriptResource.axd" preCondition="integratedMode" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</handlers>
</system.webServer>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1" appliesTo="v2.0.50727">
<dependentAssembly>
<assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>
<bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35"/>
<bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
</dependentAssembly>
</assemblyBinding>
</runtime>
</configuration>
.NET 4.0 Web.config<?xml version="1.0"?>
<configuration>
<system.web>
<compilation debug="true" targetFramework="4.0">
</compilation>
<pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"/></system.web>
</configuration>
下面是 webservice.asmx/webservice.cs 的代码:
<%@ WebService Language="C#" CodeBehind="~/App_Code/webservice.cs" Class="webservice" %>
为类添加属性 ScriptService, 并对类中的方法使用属性 ScriptMethod, 可以让 javascript 来调用这些方法. 这里不需要再使用 JavaScriptSerializer 将对象转化为 JSON 字符串, 而是直接返回对象即可. 上面的代码中返回了 SortedDictionary, 在 .NET 2.0, 3.0 中将类似于using System;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.Script.Services;
using System.Web.Script.Serialization;
using System.Collections.Generic;
[WebService ( Namespace = "http://tempuri.org/" )]
[WebServiceBinding ( ConformsTo = WsiProfiles.BasicProfile1_1 )]
[ScriptService]
public class webservice : System.Web.Services.WebService
{
[WebMethod]
[ScriptMethod]
public SortedDictionary<string, object> Save ( string name )
{
this.Context.Response.Cache.SetNoStore ( );
SortedDictionary<string, object> values = new SortedDictionary<string, object> ( );
values.Add ( "message",
string.IsNullOrEmpty ( name ) ? "无名氏" :
string.Format ( "你好 {0}, {1}", name, DateTime.Now ) );
return values;
}
}
{ "message": "你好 x, 20xx-xx-xx xx:xx:xx" }的形式, 而对于 .NET 3.5, 4.0 则是{ "d": { "message": "你好 x, 20xx-xx-xx xx:xx:xx" } }, 因此可以分别在 jQuery 中使用下面的函数来接受 JSON:
如果 javascript 函数写在属性中, 则可以使用function(data){
alert(data.message);
}
function(data){
alert(data.d.message);
}
-:data来表示 JSON, 在不同版本中将自动替换为 data 或者 data.d:
<je:Button ID="cmdWNet4" runat="server" Label="all version">
<ClickAsync Url="webservice.asmx" MethodName="Save" Success="
function(data){
alert(-:data.message);
}
">
</ClickAsync>
</je:Button>
相关内容
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通过 Parameter 对象添加 Ajax 请求时的参数
修订历史
2011-12-5: 修改下载的链接.
2011-12-9: 增加 -:data 的使用说明.