SessionStateUtility SessionStateUtility SessionStateUtility SessionStateUtility Class

Définition

Fournit des méthodes d’assistance utilisées par les modules d’état de session et les fournisseurs de magasin d’état de session pour gérer les informations de session pour une application ASP.NET.Provides helper methods used by session-state modules and session-state store providers to manage session information for an ASP.NET application. Cette classe ne peut pas être héritée.This class cannot be inherited.

public ref class SessionStateUtility abstract sealed
public static class SessionStateUtility
type SessionStateUtility = class
Public Class SessionStateUtility
Héritage
SessionStateUtilitySessionStateUtilitySessionStateUtilitySessionStateUtility

Exemples

L’exemple de code suivant montre une implémentation de module d’état de session personnalisé qui stocke les informations de session dans la mémoire à l’aide un Hashtable.The following code example shows a custom session-state module implementation that stores session information in memory using a Hashtable. Le module utilise la SessionStateUtility classe pour référencer les HttpContext et SessionIDManager, récupérer actuel HttpStaticObjectsCollectionet déclencher la Session_OnEnd événement défini dans le fichier Global.asax pour ASP.NET application.The module uses the SessionStateUtility class to reference the current HttpContext and SessionIDManager, retrieve the current HttpStaticObjectsCollection, and raise the Session_OnEnd event defined in the Global.asax file for the ASP.NET application. Cette application n’empêche pas les demandes Web simultanées utilisant le même identificateur de session.This application does not prevent simultaneous Web requests from using the same session identifier.

using System;
using System.Web;
using System.Web.SessionState;
using System.Collections;
using System.Threading;
using System.Web.Configuration;
using System.Configuration;

namespace Samples.AspNet.SessionState
{

    public sealed class MySessionStateModule : IHttpModule, IDisposable
    {
        private Hashtable pSessionItems = new Hashtable();
        private Timer pTimer;
        private int pTimerSeconds = 10;
        private bool pInitialized = false;
        private int pTimeout;
        private HttpCookieMode pCookieMode = HttpCookieMode.UseCookies;
        private ReaderWriterLock pHashtableLock = new ReaderWriterLock();
        private ISessionIDManager pSessionIDManager;
        private SessionStateSection pConfig;


        // The SessionItem class is used to store data for a particular session along with
        // an expiration date and time. SessionItem objects are added to the local Hashtable
        // in the OnReleaseRequestState event handler and retrieved from the local Hashtable
        // in the OnAcquireRequestState event handler. The ExpireCallback method is called
        // periodically by the local Timer to check for all expired SessionItem objects in the
        // local Hashtable and remove them.

        private class SessionItem
        {
            internal SessionStateItemCollection Items;
            internal HttpStaticObjectsCollection StaticObjects;
            internal DateTime Expires;
        }


        //
        // IHttpModule.Init
        //

        public void Init(HttpApplication app)
        {
            // Add event handlers.
            app.AcquireRequestState += new EventHandler(this.OnAcquireRequestState);
            app.ReleaseRequestState += new EventHandler(this.OnReleaseRequestState);

            // Create a SessionIDManager.
            pSessionIDManager = new SessionIDManager();
            pSessionIDManager.Initialize();

            // If not already initialized, initialize timer and configuration.
            if (!pInitialized)
            {
                lock (typeof(MySessionStateModule))
                {
                    if (!pInitialized)
                    {
                        // Create a Timer to invoke the ExpireCallback method based on
                        // the pTimerSeconds value (e.g. every 10 seconds).

                        pTimer = new Timer(new TimerCallback(this.ExpireCallback),
                                           null,
                                           0,
                                           pTimerSeconds * 1000);

                        // Get the configuration section and set timeout and CookieMode values.
                        Configuration cfg =
                          WebConfigurationManager.OpenWebConfiguration(System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath);
                        pConfig = (SessionStateSection)cfg.GetSection("system.web/sessionState");

                        pTimeout = (int)pConfig.Timeout.TotalMinutes;
                        pCookieMode = pConfig.Cookieless;

                        pInitialized = true;
                    }
                }
            }
        }



        //
        // IHttpModule.Dispose
        //

        public void Dispose()
        {
            if (pTimer != null)
            {
                this.pTimer.Dispose();
               ((IDisposable)pTimer).Dispose();
            }
        }


        //
        // Called periodically by the Timer created in the Init method to check for 
        // expired sessions and remove expired data.
        //

        void ExpireCallback(object state)
        {
            try
            {
                pHashtableLock.AcquireWriterLock(Int32.MaxValue);

                this.RemoveExpiredSessionData();

            }
            finally
            {
                pHashtableLock.ReleaseWriterLock();
            }
        }


        //
        // Recursivly remove expired session data from session collection.
        //
        private void RemoveExpiredSessionData()
        {
            string sessionID;

            foreach (DictionaryEntry entry in pSessionItems)
            {
                SessionItem item = (SessionItem)entry.Value;

                if ( DateTime.Compare(item.Expires, DateTime.Now)<=0 )
                {
                    sessionID = entry.Key.ToString();
                    pSessionItems.Remove(entry.Key);

                    HttpSessionStateContainer stateProvider =
                      new HttpSessionStateContainer(sessionID,
                                                   item.Items,
                                                   item.StaticObjects,
                                                   pTimeout,
                                                   false,
                                                   pCookieMode,
                                                   SessionStateMode.Custom,
                                                   false);

                    SessionStateUtility.RaiseSessionEnd(stateProvider, this, EventArgs.Empty);
                    this.RemoveExpiredSessionData();
                    break;
                }
            }

        }


        //
        // Event handler for HttpApplication.AcquireRequestState
        //

        private void OnAcquireRequestState(object source, EventArgs args)
        {
            HttpApplication app = (HttpApplication)source;
            HttpContext context = app.Context;
            bool isNew = false;
            string sessionID;
            SessionItem sessionData = null;
            bool supportSessionIDReissue = true;

            pSessionIDManager.InitializeRequest(context, false, out supportSessionIDReissue);
            sessionID = pSessionIDManager.GetSessionID(context);


            if (sessionID != null)
            {
                try
                {
                    pHashtableLock.AcquireReaderLock(Int32.MaxValue);
                    sessionData = (SessionItem)pSessionItems[sessionID];

                    if (sessionData != null)
                       sessionData.Expires = DateTime.Now.AddMinutes(pTimeout);
                }
                finally
                {
                    pHashtableLock.ReleaseReaderLock();
                }
            }
            else
            {
                bool redirected, cookieAdded;

                sessionID = pSessionIDManager.CreateSessionID(context);
                pSessionIDManager.SaveSessionID(context, sessionID, out redirected, out cookieAdded);

                if (redirected)
                    return;
            }

            if (sessionData == null)
            {
                // Identify the session as a new session state instance. Create a new SessionItem
                // and add it to the local Hashtable.

                isNew = true;

                sessionData = new SessionItem();

                sessionData.Items = new SessionStateItemCollection();
                sessionData.StaticObjects = SessionStateUtility.GetSessionStaticObjects(context);
                sessionData.Expires = DateTime.Now.AddMinutes(pTimeout);

                try
                {
                    pHashtableLock.AcquireWriterLock(Int32.MaxValue);
                    pSessionItems[sessionID] = sessionData;
                }
                finally
                {
                    pHashtableLock.ReleaseWriterLock();
                }
            }

            // Add the session data to the current HttpContext.
            SessionStateUtility.AddHttpSessionStateToContext(context,
                             new HttpSessionStateContainer(sessionID,
                                                          sessionData.Items,
                                                          sessionData.StaticObjects,
                                                          pTimeout,
                                                          isNew,
                                                          pCookieMode,
                                                          SessionStateMode.Custom,
                                                          false));

            // Execute the Session_OnStart event for a new session.
            if (isNew && Start != null)
            {
                Start(this, EventArgs.Empty);
            }
        }

        //
        // Event for Session_OnStart event in the Global.asax file.
        //

        public event EventHandler Start;


        //
        // Event handler for HttpApplication.ReleaseRequestState
        //

        private void OnReleaseRequestState(object source, EventArgs args)
        {
            HttpApplication app = (HttpApplication)source;
            HttpContext context = app.Context;
            string sessionID;

            // Read the session state from the context
            HttpSessionStateContainer stateProvider =
              (HttpSessionStateContainer)(SessionStateUtility.GetHttpSessionStateFromContext(context));

            // If Session.Abandon() was called, remove the session data from the local Hashtable
            // and execute the Session_OnEnd event from the Global.asax file.
            if (stateProvider.IsAbandoned)
            {
                try
                {
                    pHashtableLock.AcquireWriterLock(Int32.MaxValue);

                    sessionID = pSessionIDManager.GetSessionID(context);
                    pSessionItems.Remove(sessionID);
                }
                finally
                {
                    pHashtableLock.ReleaseWriterLock();
                }

                SessionStateUtility.RaiseSessionEnd(stateProvider, this, EventArgs.Empty);
            }

            SessionStateUtility.RemoveHttpSessionStateFromContext(context);
        }


    }
}
Imports System
Imports System.Web
Imports System.Web.SessionState
Imports System.Collections
Imports System.Threading
Imports System.Web.Configuration
Imports System.Configuration

Namespace Samples.AspNet.SessionState

    Public NotInheritable Class MySessionStateModule
        Implements IHttpModule, IDisposable

        Private pSessionItems As Hashtable = New Hashtable()
        Private pTimer As Timer
        Private pTimerSeconds As Integer = 10
        Private pInitialized As Boolean = False
        Private pTimeout As Integer
        Private pCookieMode As HttpCookieMode = HttpCookieMode.UseCookies
        Private pHashtableLock As ReaderWriterLock = New ReaderWriterLock()
        Private pSessionIDManager As ISessionIDManager
        Private pConfig As SessionStateSection


        ' The SessionItem class is used to store data for a particular session along with
        ' an expiration date and time. SessionItem objects are added to the local Hashtable
        ' in the OnReleaseRequestState event handler and retrieved from the local Hashtable
        ' in the OnAcquireRequestState event handler. The ExpireCallback method is called
        ' periodically by the local Timer to check for all expired SessionItem objects in the
        ' local Hashtable and remove them. 
        Private Class SessionItem
            Friend Items As SessionStateItemCollection
            Friend StaticObjects As HttpStaticObjectsCollection
            Friend Expires As DateTime
        End Class



        '
        ' IHttpModule.Init
        '
        
	Public Sub Init(ByVal app As HttpApplication) Implements IHttpModule.Init
            ' Add event handlers.
            AddHandler app.AcquireRequestState, New EventHandler(AddressOf Me.OnAcquireRequestState)
            AddHandler app.ReleaseRequestState, New EventHandler(AddressOf Me.OnReleaseRequestState)

            ' Create a SessionIDManager.
            pSessionIDManager = New SessionIDManager()
            pSessionIDManager.Initialize()

            ' If not already initialized, initialize timer and configuration.
            If Not pInitialized Then
                SyncLock GetType(MySessionStateModule)
                    If Not pInitialized Then
                        ' Create a Timer to invoke the ExpireCallback method based on
                        ' the pTimerSeconds value (e.g. every 10 seconds).
                        pTimer = New Timer(New TimerCallback(AddressOf Me.ExpireCallback), _
                                           Nothing, _
                                           0, _
                                           pTimerSeconds * 1000)

                        ' Get the configuration section and set timeout and CookieMode values.
                        Dim cfg As System.Configuration.Configuration = _
                          WebConfigurationManager.OpenWebConfiguration( _
                            System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath)
                        pConfig = CType(cfg.GetSection("system.web/sessionState"), SessionStateSection)

                        pTimeout = CInt(pConfig.Timeout.TotalMinutes)
                        pCookieMode = pConfig.Cookieless

                        pInitialized = True
                    End If
                End SyncLock
            End If
        End Sub



        '
        ' IHttpModule.Dispose
        '
        Public Sub Dispose() Implements IHttpModule.Dispose, IDisposable.Dispose
            If Not pTimer Is Nothing Then CType(pTimer, IDisposable).Dispose()
        End Sub


        '
        ' Called periodically by the Timer created in the Init method to check for 
        ' expired sessions and remove expired data.
        '
        Sub ExpireCallback(ByVal state As Object)
            Try
                pHashtableLock.AcquireWriterLock(Int32.MaxValue)

                Me.RemoveExpiredSessionData()

            Finally
                pHashtableLock.ReleaseWriterLock()
            End Try

        End Sub

        '
        ' Recursivly remove expired session data from session collection.
        '
        Private Sub RemoveExpiredSessionData()
            Dim sessionID As String
            Dim entry As DictionaryEntry

            For Each entry In pSessionItems
                Dim item As SessionItem = CType(entry.Value, SessionItem)

                If DateTime.Compare(item.Expires, DateTime.Now) <= 0 Then
                    sessionID = entry.Key.ToString()
                    pSessionItems.Remove(entry.Key)

                    Dim stateProvider As HttpSessionStateContainer = _
                      New HttpSessionStateContainer(sessionID, _
                                                   item.Items, _
                                                   item.StaticObjects, _
                                                   pTimeout, _
                                                   False, _
                                                   pCookieMode, _
                                                   SessionStateMode.Custom, _
                                                   False)

                    SessionStateUtility.RaiseSessionEnd(stateProvider, Me, EventArgs.Empty)
                    Me.RemoveExpiredSessionData()
                    Exit For
                End If
            Next entry
        End Sub


    	
        '
        ' Event handler for HttpApplication.AcquireRequestState
        '
        Private Sub OnAcquireRequestState(ByVal [source] As Object, ByVal args As EventArgs)
            Dim app As HttpApplication = CType([source], HttpApplication)
            Dim context As HttpContext = app.Context
            Dim isNew As Boolean = False
            Dim sessionID As String
            Dim sessionData As SessionItem = Nothing
            Dim supportSessionIDReissue As Boolean = True

            pSessionIDManager.InitializeRequest(context, False, supportSessionIDReissue)
            sessionID = pSessionIDManager.GetSessionID(context)


            If Not (sessionID Is Nothing) Then
                Try
                    pHashtableLock.AcquireReaderLock(Int32.MaxValue)
                    sessionData = CType(pSessionItems(sessionID), SessionItem)

                    If Not (sessionData Is Nothing) Then
                        sessionData.Expires = DateTime.Now.AddMinutes(pTimeout)
                    End If
                Finally
                    pHashtableLock.ReleaseReaderLock()
                End Try
            Else
                Dim redirected, cookieAdded As Boolean

                sessionID = pSessionIDManager.CreateSessionID(context)
                pSessionIDManager.SaveSessionID(context, sessionID, redirected, cookieAdded)

                If redirected Then Return
            End If
            If sessionData Is Nothing Then
                ' Identify the session as a new session state instance. Create a new SessionItem
                ' and add it to the local Hashtable.
                isNew = True

                sessionData = New SessionItem()

                sessionData.Items = New SessionStateItemCollection()
                sessionData.StaticObjects = SessionStateUtility.GetSessionStaticObjects(context)
                sessionData.Expires = DateTime.Now.AddMinutes(pTimeout)

                Try
                    pHashtableLock.AcquireWriterLock(Int32.MaxValue)
                    pSessionItems(sessionID) = sessionData
                Finally
                    pHashtableLock.ReleaseWriterLock()
                End Try
            End If

            ' Add the session data to the current HttpContext.
            SessionStateUtility.AddHttpSessionStateToContext(context, _
                             New HttpSessionStateContainer(sessionID, _
                                                          sessionData.Items, _
                                                          sessionData.StaticObjects, _
                                                          pTimeout, _
                                                          isNew, _
                                                          pCookieMode, _
                                                          SessionStateMode.Custom, _
                                                          False))

            ' Execute the Session_OnStart event for a new session.
            If isNew Then RaiseEvent Start(Me, EventArgs.Empty)
        End Sub


        '
        ' Event for Session_OnStart event in the Global.asax file.
        '
	Public Event Start As EventHandler


	
        '
        ' Event handler for HttpApplication.ReleaseRequestState
        '
        Private Sub OnReleaseRequestState(ByVal [source] As Object, ByVal args As EventArgs)
            Dim app As HttpApplication = CType([source], HttpApplication)
            Dim context As HttpContext = app.Context
            Dim sessionID As String

            ' Read the session state from the context
            Dim stateProvider As HttpSessionStateContainer = _
               CType(SessionStateUtility.GetHttpSessionStateFromContext(context), HttpSessionStateContainer)

            ' If Session.Abandon() was called, remove the session data from the local Hashtable
            ' and execute the Session_OnEnd event from the Global.asax file.
            If stateProvider.IsAbandoned Then
                Try
                    pHashtableLock.AcquireWriterLock(Int32.MaxValue)

                    sessionID = pSessionIDManager.GetSessionID(context)
                    pSessionItems.Remove(sessionID)
                Finally
                    pHashtableLock.ReleaseWriterLock()
                End Try

                SessionStateUtility.RaiseSessionEnd(stateProvider, Me, EventArgs.Empty)
            End If

          SessionStateUtility.RemoveHttpSessionStateFromContext(context)
        End Sub
    
    End Class
End Namespace

Pour utiliser ce module d’état de session personnalisé dans une application ASP.NET, vous pouvez remplacer la SessionStateModule référencer dans le fichier Web.config, comme indiqué dans l’exemple suivant.To use this custom session-state module in an ASP.NET application, you can replace the existing SessionStateModule reference in the Web.config file, as shown in the following example.

<configuration>  
  <system.web>  
    <httpModules>  
      <remove name="Session" />  
      <add name="Session"  
      type="Samples.AspNet.SessionState.MySessionStateModule" />  
    </httpModules>  
  </system.web>  
</configuration>  

Remarques

Le SessionStateUtility classe fournit des méthodes d’assistance statiques qui sont utilisées par un module d’état de session ou un fournisseur de magasin d’état de session.The SessionStateUtility class provides static helper methods that are used by a session-state module or a session-state store provider. Les développeurs d’applications seront inutile d’appeler ces méthodes à partir de leur code.Application developers will not need to call these methods from their code.

Le tableau suivant décrit les utilisations du module d’état de session et du fournisseur de magasins d’état de session les méthodes.The following table describes the ways the session-state module and session-state store provider use the methods.

MéthodeMethod UtilisezUse
Méthode GetHttpSessionStateFromContextGetHttpSessionStateFromContext method Utilisable par les modules d’état de session personnalisés pour récupérer les informations de session pour une session existante ou créer les informations de session pour une nouvelle session.Can be used by custom session-state modules to either retrieve session information for an existing session or create session information for a new session.
Méthode AddHttpSessionStateToContextAddHttpSessionStateToContext method Appelée par le module d’état de session pour ajouter les données de session actuel HttpContext et rendez-le accessible au code d’application via le Session propriété.Called by the session-state module to add the session data to the current HttpContext and make it available to application code through the Session property.
Méthode RemoveHttpSessionStateFromContextRemoveHttpSessionStateFromContext method Appelée par le module d’état de session au cours de la ReleaseRequestState ou EndRequest événements à la fin d’une demande, pour effacer les données de session à partir du HttpContext.Called by the session-state module during the ReleaseRequestState or EndRequest events at the end of a request, to clear session data from the current HttpContext.
Méthode GetSessionStaticObjectsGetSessionStaticObjects method Appelée par le module d’état de session pour obtenir une référence à la StaticObjects collection basée sur les objets définis dans le fichier Global.asax.Called by the session-state module to get a reference to the StaticObjects collection based on objects defined in the Global.asax file. Le HttpStaticObjectsCollection collection retournée est incluse avec les données de session ajoutées à l’actuel HttpContext.The HttpStaticObjectsCollection collection returned is included with the session data added to the current HttpContext.

Données de session sont passées à et récupérées à partir du HttpContext comme un HttpSessionStateContainer objet ou une implémentation valide de le IHttpSessionState interface.Session data is passed to and retrieved from the current HttpContext as an HttpSessionStateContainer object or any valid implementation of the IHttpSessionState interface.

Pour plus d’informations sur l’implémentation d’un fournisseur de magasin d’état de session, consultez implémentation d’un fournisseur de Store d’état de Session.For information about implementing a session-state store provider, see Implementing a Session-State Store Provider.

Propriétés

SerializationSurrogateSelector SerializationSurrogateSelector SerializationSurrogateSelector SerializationSurrogateSelector

Obtient ou définit un sélecteur de substitution de sérialisation qui est utilisé pour la personnalisation de sérialisation de session.Gets or sets a serialization surrogate selector that is used for session serialization customization.

Méthodes

AddHttpSessionStateToContext(HttpContext, IHttpSessionState) AddHttpSessionStateToContext(HttpContext, IHttpSessionState) AddHttpSessionStateToContext(HttpContext, IHttpSessionState) AddHttpSessionStateToContext(HttpContext, IHttpSessionState)

Applique les données de session au contexte pour la demande actuelle.Applies the session data to the context for the current request.

GetHttpSessionStateFromContext(HttpContext) GetHttpSessionStateFromContext(HttpContext) GetHttpSessionStateFromContext(HttpContext) GetHttpSessionStateFromContext(HttpContext)

Récupère les données de session dans le contexte pour la demande actuelle.Retrieves session data from the context for the current request.

GetSessionStaticObjects(HttpContext) GetSessionStaticObjects(HttpContext) GetSessionStaticObjects(HttpContext) GetSessionStaticObjects(HttpContext)

Obtient une référence à la collection d'objets statiques pour le contexte spécifié.Gets a reference to the static objects collection for the specified context.

IsSessionStateReadOnly(HttpContext) IsSessionStateReadOnly(HttpContext) IsSessionStateReadOnly(HttpContext) IsSessionStateReadOnly(HttpContext)

Récupère une valeur qui indique si l’état de la session est en lecture seule pour le HttpContext spécifié.Gets a value which indicates whether the session state is read-only for the specified HttpContext.

IsSessionStateRequired(HttpContext) IsSessionStateRequired(HttpContext) IsSessionStateRequired(HttpContext) IsSessionStateRequired(HttpContext)

Obtient une valeur qui indique si l’état de la session est nécessaire pour l’objet HttpContext spécifié.Gets a value which indicates whether the session state is required for the specified HttpContext.

RaiseSessionEnd(IHttpSessionState, Object, EventArgs) RaiseSessionEnd(IHttpSessionState, Object, EventArgs) RaiseSessionEnd(IHttpSessionState, Object, EventArgs) RaiseSessionEnd(IHttpSessionState, Object, EventArgs)

Exécute l’événement Session_OnEnd défini dans le fichier Global.asax de l’application ASP.NET.Executes the Session_OnEnd event defined in the Global.asax file for the ASP.NET application.

RemoveHttpSessionStateFromContext(HttpContext) RemoveHttpSessionStateFromContext(HttpContext) RemoveHttpSessionStateFromContext(HttpContext) RemoveHttpSessionStateFromContext(HttpContext)

Supprime des données de session du contexte spécifié.Removes session data from the specified context.

S’applique à

Voir aussi