在方法中使用Session

•ASP.NET中每个请求都由一个IHttpHandler对象来处理
•在处理时要使用Session则需要让Handler对象实现IRequiresSessionState接口
•RestHandlerFactory根据所请求的方法的标记来选择是否启用Session
•启用方法：在WebMethodAttribute中标记
–EnableSession属性设为true

aspx

    <form id="form1" runat="server">
        <asp:ScriptManager runat="server" ID="ScriptManager1" ScriptMode="Debug">
            <Services>
                <asp:ServiceReference Path="Services/EnableSessionService.asmx" InlineScript="true" />
            </Services>
        </asp:ScriptManager>    
        
        <input type="button" value="Add One" onclick="addOne()" />
    
        <script language="javascript" type="text/javascript">
            function addOne()
            {
                EnableSessionService.AddOne(onSucceeded);
            }
            
            function onSucceeded(result)
            {
                alert(result);
            }
        </script>        
    </form>

EnableSessionService.asmx

<%@ WebService Language="C#" Class="EnableSessionService" %>

using System;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.Script.Services;
using System.Web.SessionState;

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[ScriptService]
public class EnableSessionService  : System.Web.Services.WebService
{
    [WebMethod(true)]
    public int AddOne()
    {
        HttpSessionState session = HttpContext.Current.Session;

        object objValue = session["value"];
        int value = objValue == null ? 0 : (int)objValue;
        value++;
        session["value"] = value;
        return value;
    }
    
}

WebService方法加上[WebMethod(true)]修饰即可使用session