sdk/samples/all in on code/Visual Studio 2010/CSASPNETShareSessionBetweenSubDomains/CSASPNETShareSessionBetweenSubDomainsModule/SharedSessionModule.cs

   1 /****************************** Module Header ******************************\
   2 * Module Name:    SharedSessionModule.cs
   3 * Project:        CSASPNETShareSessionBetweenSubDomains
   4 * Copyright (c) Microsoft Corporation
   5 *
   6 * This project demonstrates how to configure a SQL Server as SessionState and
   7 * make a module to share Session between two Web Sites with the same root domain.
   8 *
   9 * SharedSessionModule is used to make Web Sites use the same Application Id and
  10 * Session Id to achieve sharing Session.
  11 *
  12 * This source is subject to the Microsoft Public License.
  13 * See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  14 * All other rights reserved.
  15 *
  16 \*****************************************************************************/
  17
  18 using System;
  19 using System.Web;
  20 using System.Reflection;
  21 using System.Configuration;
  22
  23 namespace CSASPNETShareSessionBetweenSubDomainsModule
  24 {
  25     /// <summary>
  26     /// A HttpModule used for sharing the session between Applications in
  27     /// sub domains.
  28     /// </summary>
  29     public class SharedSessionModule : IHttpModule
  30     {
  31         // Cache settings on memory.
  32         protected static string applicationName = ConfigurationManager.AppSettings["ApplicationName"];
  33         protected static string rootDomain = ConfigurationManager.AppSettings["RootDomain"];
  34
  35         #region IHttpModule Members
  36         /// <summary>
  37         /// Initializes a module and prepares it to handle requests.
  38         /// </summary>
  39         /// <param name="context">
  40         /// An System.Web.HttpApplication
  41         /// that provides access to the methods,
  42         /// properties, and events common to all application objects within
  43         /// an ASP.NET application.
  44         /// </param>
  45         public void Init(HttpApplication context)
  46         {
  47             // This module requires both Application Name and Root Domain to work.
  48             if (string.IsNullOrEmpty(applicationName) ||
  49                 string.IsNullOrEmpty(rootDomain))
  50             {
  51                 return;
  52             }
  53
  54             // Change the Application Name in runtime.
  55             FieldInfo runtimeInfo = typeof(HttpRuntime).GetField("_theRuntime",
  56                 BindingFlags.Static | BindingFlags.NonPublic);
  57             HttpRuntime theRuntime = (HttpRuntime)runtimeInfo.GetValue(null);
  58             FieldInfo appNameInfo = typeof(HttpRuntime).GetField("_appDomainAppId",
  59                 BindingFlags.Instance | BindingFlags.NonPublic);
  60
  61             appNameInfo.SetValue(theRuntime, applicationName);
  62
  63             // Subscribe Events.
  64             context.PostRequestHandlerExecute += new EventHandler(context_PostRequestHandlerExecute);
  65         }
  66
  67         /// <summary>
  68         /// Disposes of the resources (other than memory) used by the module
  69         /// that implements.
  70         /// </summary>
  71         public void Dispose()
  72         {
  73         }
  74         #endregion
  75
  76         /// <summary>
  77         /// Before sending response content to client, change the Cookie to Root Domain
  78         /// and store current Session Id.
  79         /// </summary>
  80         /// <param name="sender">
  81         /// An instance of System.Web.HttpApplication that provides access to
  82         /// the methods, properties, and events common to all application
  83         /// objects within an ASP.NET application.
  84         /// </param>
  85         void context_PostRequestHandlerExecute(object sender, EventArgs e)
  86         {
  87             HttpApplication context = (HttpApplication)sender;
  88
  89             // ASP.NET store a Session Id in cookie to specify current Session.
  90             HttpCookie cookie = context.Response.Cookies["ASP.NET_SessionId"];
  91
  92             if (context.Session != null &&
  93                 !string.IsNullOrEmpty(context.Session.SessionID))
  94             {
  95                 // Need to store current Session Id during every request.
  96                 cookie.Value = context.Session.SessionID;
  97
  98                 // All Applications use one root domain to store this Cookie
  99                 // So that it can be shared.
 100                 if (rootDomain != "localhost")
 101                 {
 102                     cookie.Domain = rootDomain;
 103                 }
 104
 105                 // All Virtual Applications and Folders share this Cookie too.
 106                 cookie.Path = "/";
 107             }
 108         }
 109     }
 110 }