SessionStateUtility.GetHttpSessionStateFromContext(HttpContext) Method

Definition

Namespace:

System.Web.SessionState

Assembly:

System.Web.dll

Retrieves session data from the context for the current request.

public:
 static System::Web::SessionState::IHttpSessionState ^ GetHttpSessionStateFromContext(System::Web::HttpContext ^ context);

public static System.Web.SessionState.IHttpSessionState GetHttpSessionStateFromContext (System.Web.HttpContext context);

static member GetHttpSessionStateFromContext : System.Web.HttpContext -> System.Web.SessionState.IHttpSessionState

Public Shared Function GetHttpSessionStateFromContext (context As HttpContext) As IHttpSessionState

Parameters

context

HttpContext

The HttpContext from which to retrieve session data.

Returns

IHttpSessionState

An IHttpSessionState implementation instance populated with session data from the current request.

Examples

The following code example shows the handler for the ReleaseRequestState event in a custom session-state module. The module retrieves session data from the HttpContext for the current request using the GetHttpSessionStateFromContext method. This code example is part of a larger example provided for the SessionStateUtility class.

//
// 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);
}

'
' 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

Remarks

The GetHttpSessionStateFromContext method can be used by a session-state module to retrieve session data from the current request. This occurs during the ReleaseRequestState event at the end of a request. The returned session data can then be written to the session data store. If the session has been abandoned, the session data can be removed from the data store and HttpContext, and the Session_OnEnd event can be executed.

Notes to Inheritors

You can use the RemoveHttpSessionStateFromContext(HttpContext) method to remove session data from the internal store, and the RaiseSessionEnd(IHttpSessionState, Object, EventArgs) method to raise the Session_OnEnd event.