不废话了，直奔主题吧

wcf端：

近几年比较流行restful，为了能让ajax调用，同时也为了支持restful风格的uri，在创建一个Ajax-enabled Wcf Service后，必须手动修改svc文件，指定Factory，即：

<%@ ServiceHost Language="C#" Debug="true" Service="ajaxSample.HelloWorld" CodeBehind="HelloWorld.svc.cs" Factory="System.ServiceModel.Activation.WebServiceHostFactory" %>

注：如果不添加Factory，则wcf将无法用类似http://localhost/helloWorld.svc/Hello/person/name 的restful方式直接访问。

同时还要去掉web.config中的<enableWebScript />即类似:

<system.serviceModel>
<behaviors>
<endpointBehaviors>
<behavior name="ajaxSample.HelloWorldAspNetAjaxBehavior">
<!--<enableWebScript />-->
</behavior>
</endpointBehaviors>
</behaviors>
<serviceHostingEnvironment aspNetCompatibilityEnabled="true"
multipleSiteBindingsEnabled="true" />
<services>
<service name="ajaxSample.HelloWorld">
<endpoint address="" behaviorConfiguration="ajaxSample.HelloWorldAspNetAjaxBehavior"
binding="webHttpBinding" contract="ajaxSample.HelloWorld" />
</service>
</services>
</system.serviceModel>

好了，开始写代码，鉴于wcf调用时有GET/POST二种方式，下面把几种常用的情况都写一个示例方法：
复制代码 代码如下:
using System.Collections.Generic;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.ServiceModel.Web;

namespace ajaxSample
{
[ServiceContract(Namespace = "http://yjmyzz.cnblogs.com/")]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class HelloWorld
{

/// <summary>
/// 只能Post的Restful方法
/// </summary>
/// <param name="person"></param>
/// <param name="welcome"></param>
/// <returns></returns>
[OperationContract]
[WebInvoke(Method = "POST", UriTemplate = "PostRestfulTest/{person}/{welcome}", ResponseFormat = WebMessageFormat.Json)]
public List<string> PostRestfulTest(string person,string welcome)
{
List<string> result = new List<string>();

result.Add("PostRestfulTest -> from server:");
result.Add(person);
result.Add(welcome);
return result;
}

/// <summary>
/// 只能Get的Restful方法
/// </summary>
/// <param name="person"></param>
/// <param name="welcome"></param>
/// <returns></returns>
[OperationContract]
[WebInvoke(Method = "GET", UriTemplate = "GETRestfulTest/{person}/{welcome}", ResponseFormat = WebMessageFormat.Json)]
public List<string> GETRestfulTest(string person, string welcome)
{
List<string> result = new List<string>();

result.Add("GETRestfulTest -> from server:");
result.Add(person);
result.Add(welcome);
return result;
}

/// <summary>
/// 即可Get与Post的Restful方法
/// </summary>
/// <param name="person"></param>
/// <param name="welcome"></param>
/// <returns></returns>
[OperationContract]
[WebInvoke(Method = "*", UriTemplate = "RestfulTest/{person}/{welcome}", ResponseFormat = WebMessageFormat.Json)]
public List<string> RestfulTest(string person, string welcome)
{
List<string> result = new List<string>();

result.Add("RestfulTest -> from server:");
result.Add(person);
result.Add(welcome);
return result;
}


/// <summary>
/// 只能Post的常规方法(注：Post方式，BodyStyle必须设置成WrappedRequest或Wrapped)
/// </summary>
/// <param name="person"></param>
/// <param name="welcome"></param>
/// <returns></returns>
[OperationContract]
[WebInvoke(Method = "POST", ResponseFormat = WebMessageFormat.Json, BodyStyle=WebMessageBodyStyle.WrappedRequest)]
public List<string> PostTest(string person, string welcome)
{
List<string> result = new List<string>();

result.Add("PostRestfulTest -> from server:");
result.Add(person);
result.Add(welcome);
return result;
}

/// <summary>
/// 只能Get的常规方法
/// </summary>
/// <param name="person"></param>
/// <param name="welcome"></param>
/// <returns></returns>
[OperationContract]
[WebInvoke(Method = "GET", ResponseFormat = WebMessageFormat.Json)]
public List<string> GETTest(string person, string welcome)
{
List<string> result = new List<string>();

result.Add("GETTest -> from server:");
result.Add(person);
result.Add(welcome);
return result;
}




}
}

jQuery调用代码：
复制代码 代码如下:
<script type="text/javascript">
$().ready(function () {


$.post("HelloWorld.svc/PostRestfulTest/111/222", function (data) {
alert("PostRestfulTest调用成功，返回值为：" + data);
})

$.get("HelloWorld.svc/GETRestfulTest/333/444", function (data) {
alert("GETRestfulTest调用成功，返回值为：" + data);
})

$.get("HelloWorld.svc/RestfulTest/555/666", function (data) {
alert("RestfulTest GET方式调用成功，返回值为：" + data);
})


$.post("HelloWorld.svc/RestfulTest/777/888", function (data) {
alert("RestfulTest POST方式调用成功，返回值为：" + data);
})


$.get("HelloWorld.svc/GETTest", { person: "aaa", welcome: "bbb" }, function (data) {
alert("GETTest 调用成功，返回值为：" + data);
});


$.ajax({
url: "HelloWorld.svc/PostTest",
type: "POST",
contentType: "application/json",
data: '{"person":"ccc","welcome":"ddd"}',
dataType: "html",
success: function (data) { alert("PostTest调用成功，返回值为：" + data); }
});
})
</script>

有时候，WCF暴露的方法中可能需要一些敏感信息做为参数(比如用户名/用户ID之类)，这时如果直接用js来调用wcf，可能会把这部分信息泄漏在客户端，这种场景下，我们也经常用一个服务端的ashx来做中转

TestService.svc
复制代码 代码如下:
using System.ServiceModel;

namespace ashx_jQuery
{
[ServiceContract]
public class TestService
{
/// <summary>
/// 获取当前用户指定月份的工资
/// </summary>
/// <param name="userId"></param>
/// <param name="month"></param>
/// <returns></returns>
[OperationContract]
public double GetSalary(int userId,int month)
{
if (month == 1)//只是演示而已
{
return 5000;
}
else
{
return 1000;
}
}
}
}

AjaxProcess.ashx
复制代码 代码如下:
using System.Web;

namespace ashx_jQuery
{
/// <summary>
/// Summary description for AjaxProcess
/// </summary>
public class AjaxProcess : IHttpHandler
{

public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
string month = context.Request["month"];

TestService wcf = new TestService();
double salary = wcf.GetSalary(GetUserId(), int.Parse(month));
context.Response.Write("{salary:" + salary + "}");
}


/// <summary>
/// 获取当前的用户ID
/// </summary>
/// <returns></returns>
private int GetUserId()
{
return 1;
}

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

jQuery调用:
复制代码 代码如下:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="default.aspx.cs" Inherits="ashx_jQuery._default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http:///ajax/jQuery/jquery-1.7.1.min.js"></script>
<script type="text/javascript">
$().ready(function () {
$("#btnTest").click(function () {
$.post(
"AjaxProcess.ashx",
{ month:1 },
function (e) {
var d = eval("(" + e + ")");
alert(d.salary);
}, "html");
})
})
</script>
</head>
<body>
<form id="form1" runat="server">
<input type="button" value="GetSalary" id="btnTest"/>
</form>
</body>
</html>

示例代码：点击下载