IHttpSessionState Interface
Definition
Important
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Defines the contract to implement a custom session-state container.
public interface class IHttpSessionStatepublic interface IHttpSessionStatetype IHttpSessionState = interfacePublic Interface IHttpSessionState- Derived
Examples
The following code example implements the IHttpSessionState interface to create a new session-state container class named MySessionState.
using System;
using System.Web;
using System.Web.SessionState;
using System.Collections;
using System.Collections.Specialized;
using System.Text;
using System.Threading;
using System.Globalization;
namespace Samples.AspNet.SessionState
{
public sealed class MySessionState : IHttpSessionState
{
const int MAX_TIMEOUT = 24 * 60; // Timeout cannot exceed 24 hours.
string pId;
ISessionStateItemCollection pSessionItems;
HttpStaticObjectsCollection pStaticObjects;
int pTimeout;
bool pNewSession;
HttpCookieMode pCookieMode;
SessionStateMode pMode;
bool pAbandon;
bool pIsReadonly;
public MySessionState(string id,
ISessionStateItemCollection sessionItems,
HttpStaticObjectsCollection staticObjects,
int timeout,
bool newSession,
HttpCookieMode cookieMode,
SessionStateMode mode,
bool isReadonly)
{
pId = id;
pSessionItems = sessionItems;
pStaticObjects = staticObjects;
pTimeout = timeout;
pNewSession = newSession;
pCookieMode = cookieMode;
pMode = mode;
pIsReadonly = isReadonly;
}
public int Timeout
{
get { return pTimeout; }
set
{
if (value <= 0)
throw new ArgumentException("Timeout value must be greater than zero.");
if (value > MAX_TIMEOUT)
throw new ArgumentException("Timout cannot be greater than " + MAX_TIMEOUT.ToString());
pTimeout = value;
}
}
public string SessionID
{
get { return pId; }
}
public bool IsNewSession
{
get { return pNewSession; }
}
public SessionStateMode Mode
{
get { return pMode; }
}
public bool IsCookieless
{
get { return CookieMode == HttpCookieMode.UseUri; }
}
public HttpCookieMode CookieMode
{
get { return pCookieMode; }
}
//
// Abandon marks the session as abandoned. The IsAbandoned property is used by the
// session state module to perform the abandon work during the ReleaseRequestState event.
//
public void Abandon()
{
pAbandon = true;
}
public bool IsAbandoned
{
get { return pAbandon; }
}
//
// Session.LCID exists only to support legacy ASP compatibility. ASP.NET developers should use
// Page.LCID instead.
//
public int LCID
{
get { return Thread.CurrentThread.CurrentCulture.LCID; }
set { Thread.CurrentThread.CurrentCulture = CultureInfo.ReadOnly(new CultureInfo(value)); }
}
//
// Session.CodePage exists only to support legacy ASP compatibility. ASP.NET developers should use
// Response.ContentEncoding instead.
//
public int CodePage
{
get
{
if (HttpContext.Current != null)
return HttpContext.Current.Response.ContentEncoding.CodePage;
else
return Encoding.Default.CodePage;
}
set
{
if (HttpContext.Current != null)
HttpContext.Current.Response.ContentEncoding = Encoding.GetEncoding(value);
}
}
public HttpStaticObjectsCollection StaticObjects
{
get { return pStaticObjects; }
}
public object this[string name]
{
get { return pSessionItems[name]; }
set { pSessionItems[name] = value; }
}
public object this[int index]
{
get { return pSessionItems[index]; }
set { pSessionItems[index] = value; }
}
public void Add(string name, object value)
{
pSessionItems[name] = value;
}
public void Remove(string name)
{
pSessionItems.Remove(name);
}
public void RemoveAt(int index)
{
pSessionItems.RemoveAt(index);
}
public void Clear()
{
pSessionItems.Clear();
}
public void RemoveAll()
{
Clear();
}
public int Count
{
get { return pSessionItems.Count; }
}
public NameObjectCollectionBase.KeysCollection Keys
{
get { return pSessionItems.Keys; }
}
public IEnumerator GetEnumerator()
{
return pSessionItems.GetEnumerator();
}
public void CopyTo(Array items, int index)
{
foreach (object o in items)
items.SetValue(o, index++);
}
public object SyncRoot
{
get { return this; }
}
public bool IsReadOnly
{
get { return pIsReadonly; }
}
public bool IsSynchronized
{
get { return false; }
}
}
}
Imports System.Web
Imports System.Web.SessionState
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Text
Imports System.Threading
Imports System.Globalization
Namespace Samples.AspNet.SessionState
Public NotInheritable Class MySessionState
Implements IHttpSessionState
Const MAX_TIMEOUT As Integer = 24 * 60 ' Timeout cannot exceed 24 hours.
Dim pId As String
Dim pSessionItems As ISessionStateItemCollection
Dim pStaticObjects As HttpStaticObjectsCollection
Dim pTimeout As Integer
Dim pNewSession As Boolean
Dim pCookieMode As HttpCookieMode
Dim pMode As SessionStateMode
Dim pAbandon As Boolean
Dim pIsReadonly As Boolean
Public Sub New(id As String, _
sessionItems As ISessionStateItemCollection, _
staticObjects As HttpStaticObjectsCollection, _
timeout As Integer, _
newSession As Boolean, _
cookieMode As HttpCookieMode, _
mode As SessionStateMode, _
isReadonly As Boolean)
pId = id
pSessionItems = sessionItems
pStaticObjects = staticObjects
pTimeout = timeout
pNewSession = newSession
pCookieMode = cookieMode
pMode = mode
pIsReadonly = isReadonly
End Sub
Public Property Timeout As Integer Implements IHttpSessionState.Timeout
Get
Return pTimeout
End Get
Set
If value <= 0 Then _
Throw New ArgumentException("Timeout value must be greater than zero.")
If value > MAX_TIMEOUT Then _
Throw New ArgumentException("Timout cannot be greater than " & MAX_TIMEOUT.ToString())
pTimeout = value
End Set
End Property
Public ReadOnly Property SessionID As String Implements IHttpSessionState.SessionID
Get
Return pId
End Get
End Property
Public ReadOnly Property IsNewSession As Boolean Implements IHttpSessionState.IsNewSession
Get
Return pNewSession
End Get
End Property
Public ReadOnly Property Mode As SessionStateMode Implements IHttpSessionState.Mode
Get
Return pMode
End Get
End Property
Public ReadOnly Property IsCookieless As Boolean Implements IHttpSessionState.IsCookieLess
Get
Return CookieMode = HttpCookieMode.UseUri
End Get
End Property
Public ReadOnly Property CookieMode As HttpCookieMode Implements IHttpSessionState.CookieMode
Get
Return pCookieMode
End Get
End Property
'
' Abandon marks the session as abandoned. The IsAbandoned property is used by the
' session state module to perform the abandon work during the ReleaseRequestState event.
'
Public Sub Abandon() Implements IHttpSessionState.Abandon
pAbandon = True
End Sub
Public ReadOnly Property IsAbandoned As Boolean
Get
Return pAbandon
End Get
End Property
'
' Session.LCID exists only to support legacy ASP compatibility. ASP.NET developers should use
' Page.LCID instead.
'
Public Property LCID As Integer Implements IHttpSessionState.LCID
Get
Return Thread.CurrentThread.CurrentCulture.LCID
End Get
Set
Thread.CurrentThread.CurrentCulture = CultureInfo.ReadOnly(new CultureInfo(value))
End Set
End Property
'
' Session.CodePage exists only to support legacy ASP compatibility. ASP.NET developers should use
' Response.ContentEncoding instead.
'
Public Property CodePage As Integer Implements IHttpSessionState.CodePage
Get
If Not HttpContext.Current Is Nothing Then
Return HttpContext.Current.Response.ContentEncoding.CodePage
Else
Return Encoding.Default.CodePage
End If
End Get
Set
If Not HttpContext.Current Is Nothing Then _
HttpContext.Current.Response.ContentEncoding = Encoding.GetEncoding(value)
End Set
End Property
Public ReadOnly Property StaticObjects As HttpStaticObjectsCollection _
Implements IHttpSessionState.StaticObjects
Get
Return pStaticObjects
End Get
End Property
Public Property Item(name As String) As Object Implements IHttpSessionState.Item
Get
Return pSessionItems(name)
End Get
Set
pSessionItems(name) = value
End Set
End Property
Public Property Item(index As Integer) As Object Implements IHttpSessionState.Item
Get
Return pSessionItems(index)
End Get
Set
pSessionItems(index) = value
End Set
End Property
Public Sub Add(name As String, value As Object) Implements IHttpSessionState.Add
pSessionItems(name) = value
End Sub
Public Sub Remove(name As String) Implements IHttpSessionState.Remove
pSessionItems.Remove(name)
End Sub
Public Sub RemoveAt(index As Integer) Implements IHttpSessionState.RemoveAt
pSessionItems.RemoveAt(index)
End Sub
Public Sub Clear() Implements IHttpSessionState.Clear
pSessionItems.Clear()
End Sub
Public Sub RemoveAll() Implements IHttpSessionState.RemoveAll
Clear()
End Sub
Public ReadOnly Property Count As Integer Implements IHttpSessionState.Count
Get
Return pSessionItems.Count
End Get
End Property
Public ReadOnly Property Keys As NameObjectCollectionBase.KeysCollection _
Implements IHttpSessionState.Keys
Get
Return pSessionItems.Keys
End Get
End Property
Public Function GetEnumerator() As IEnumerator Implements IHttpSessionState.GetEnumerator
Return pSessionItems.GetEnumerator()
End Function
Public Sub CopyTo(items As Array, index As Integer) Implements IHttpSessionState.CopyTo
For Each o As Object In items
items.SetValue(o, index)
index += 1
Next
End Sub
Public ReadOnly Property SyncRoot As Object Implements IHttpSessionState.SyncRoot
Get
Return Me
End Get
End Property
Public ReadOnly Property IsReadOnly As Boolean Implements IHttpSessionState.IsReadOnly
Get
Return pIsReadonly
End Get
End Property
Public ReadOnly Property IsSynchronized As Boolean Implements IHttpSessionState.IsSynchronized
Get
Return False
End Get
End Property
End Class
End Namespace
Remarks
A session-state container provides access to the session-state values and related information for the current session. Session information included in a session-state container is exposed to application code through the HttpSessionState class using the Session property. The HttpSessionState class is a wrapper class for a session-state container.
The ASP.NET implementation of a session-state container is the HttpSessionStateContainer class. At the beginning of a request, during the AcquireRequestState event, the SessionStateModule creates and populates an HttpSessionStateContainer object and assigns it to the current HttpContext. At the end of a request, during the ReleaseRequestState event, the SessionStateModule retrieves the HttpSessionStateContainer object from the current HttpContext and performs any required session work, such as writing the session values to the session store, or abandoning the session. If the request is abruptly terminated, such as through a redirect, the SessionStateModule performs the same cleanup by calling the EndRequest method.
To create a custom session-state container, create a class that implements the IHttpSessionState interface. If you are creating your own custom session-state container, you must also replace the SessionStateModule with your own custom module. Your custom module will create an instance of your custom session-state container and add it to the current HttpContext using the AddHttpSessionStateToContext method. An example of a custom session-state module is included in the SessionStateUtility class overview.
Properties
| CodePage |
Gets or sets the code-page identifier for the current session. |
| CookieMode |
Gets a value that indicates whether the application is configured for cookieless sessions. |
| Count |
Gets the number of items in the session-state item collection. |
| IsCookieless |
Gets a value indicating whether the session ID is embedded in the URL or stored in an HTTP cookie. |
| IsNewSession |
Gets a value indicating whether the session was created with the current request. |
| IsReadOnly |
Gets a value indicating whether the session is read-only. |
| IsSynchronized |
Gets a value indicating whether access to the collection of session-state values is synchronized (thread safe). |
| Item[Int32] |
Gets or sets a session-state item value by numerical index. |
| Item[String] |
Gets or sets a session-state item value by name. |
| Keys |
Gets a collection of the keys for all values stored in the session-state item collection. |
| LCID |
Gets or sets the locale identifier (LCID) of the current session. |
| Mode |
Gets the current session-state mode. |
| SessionID |
Gets the unique session identifier for the session. |
| StaticObjects |
Gets a collection of objects declared by |
| SyncRoot |
Gets an object that can be used to synchronize access to the collection of session-state values. |
| Timeout |
Gets or sets the time-out period (in minutes) allowed between requests before the session-state provider terminates the session. |
Methods
| Abandon() |
Ends the current session. |
| Add(String, Object) |
Adds a new item to the session-state collection. |
| Clear() |
Clears all values from the session-state item collection. |
| CopyTo(Array, Int32) |
Copies the collection of session-state item values to a one-dimensional array, starting at the specified index in the array. |
| GetEnumerator() |
Returns an enumerator that can be used to read all the session-state item values in the current session. |
| Remove(String) |
Deletes an item from the session-state item collection. |
| RemoveAll() |
Clears all values from the session-state item collection. |
| RemoveAt(Int32) |
Deletes an item at a specified index from the session-state item collection. |
