Assembly: System.Web (in system.web.dll)
'Declaration Public ReadOnly Property AnonymousID As String 'Usage Dim instance As HttpRequest Dim value As String value = instance.AnonymousID
Property ValueA string representing the current anonymous user identifier.
The AnonymousId property assigns a long-lived unique identifier to a non-authenticated user, which can be used to track the user or assign profile properties to that user without storing data in a Session object. By default, the AnonymousId property is tracked using a cookie, but it can be set to use the URI when the Cookieless attribute in the anonymous identification configuration section is set to either the UseUri, UseDeviceProfile, or AutoDetect value. You must explicitly clear the cookie if you no longer want it available, for example when an anonymous user is authenticated.
Anonymous identification is used when there is a need to identify entities that are not authenticated and when authorization is required. For more information, see anonymousIdentification Element (ASP.NET Settings Schema)
The following code example demonstrates how to use the AnonymousId property by accessing the AnonymousIdentification_OnCreate event in the Global.asax file. This example has two parts:
A Web Forms page.
A method that handles the AnonymousIdentification_OnCreate event.
The first part of the code example shows how to use the AnonymousId property by accessing the AnonymousIdentification_OnCreate event in the Global.asax file. The AnonymousIdentification_OnCreate event is raised whenever a new anonymous ID is created.
<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) If (Application("UserCount") IsNot Nothing) Then lblUserCount.Text = Application("UserCount").ToString() lblCurrentUser.Text = Request.AnonymousID End If End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> <title>AnonymousID Example</title> </head> <body> <form id="form1" runat="server"> <div> Number of users: <asp:Label ID="lblUserCount" Runat="server"></asp:Label><br /> Current user: <asp:Label ID="lblCurrentUser" Runat="server"></asp:Label><br /> </div> </form> </body> </html>
The second part of the code example shows how to display the new AnonymousId created by the AnonymousIdentification_OnCreate event in the preceding example.
Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs) 'Initialize user count property Application("UserCount") = 0 End Sub Sub AnonymousIdentification_OnCreate(ByVal sender As Object, ByVal e As AnonymousIdentificationEventArgs) ' Change the anonymous id e.AnonymousID = "mysite.com_Anonymous_User_" & DateTime.Now.Ticks ' Increment count of unique anonymous users Application("UserCount") = Int32.Parse(Application("UserCount").ToString()) + 1 End Sub