HttpRequest.AnonymousID Property (System.Web)

.NET Framework Class Library

HttpRequest..::.AnonymousID Property

Updated: July 2009

Gets the anonymous identifier for the user, if present.

Namespace: System.Web
Assembly: System.Web (in System.Web.dll)

Syntax

Visual Basic (Declaration)

Public ReadOnly Property AnonymousID As String

Visual Basic (Usage)

Dim instance As HttpRequest
Dim value As String

value = instance.AnonymousID

public string AnonymousID { get; }

Visual C++

public:
property String^ AnonymousID {
    String^ get ();
}

JScript

public function get AnonymousID () : String

Property Value

Type: System..::.String
A string representing the current anonymous user identifier.

Remarks

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)

Examples

The following example shows how to use the AnonymousId()()() property by handling the AnonymousIdentificationModule..::.Creating event in the Global.asax file. This example has two parts:

A method in the Global.asax file that handles the AnonymousIdentificationModule..::.Creating event.
A Web Forms page.

The first part of the code example shows how to set the AnonymousId()()() property by handling the AnonymousIdentificationModule..::.Creating event in the Global.asax file. The method that is named AnonymousIdentification_Creating sets the AnonymousId()()() property when an anonymous ID is created.

Visual Basic

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)

    'Initialize user count property
    Application("UserCount") = 0

End Sub

Sub AnonymousIdentification_Creating(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

void Application_Start(Object sender, EventArgs e)
    {
        // Initialize user count property
        Application["UserCount"] = 0;
    }

public void AnonymousIdentification_Creating(Object sender, AnonymousIdentificationEventArgs e)
    {
    // 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;
}

The second part of the code example shows how to display the new AnonymousId()()() that is created by the AnonymousIdentification_Creating event handler in the preceding example.

Visual Basic

<%@ 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  >
<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>

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
  void Page_Load(object sender, EventArgs e)
    {
      if (Application["UserCount"] != null)
      {
          lblUserCount.Text = Application["UserCount"].ToString();
          lblCurrentUser.Text = Request.AnonymousID;
      }
  }    
</script>


<html  >
<head 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>

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information