Some time we need to count the online users 

If you are new to ASP.net Membership provider,

please refer http://www.revenmerchantservices.com/page/ASpnet-20-step-by-step-Membership-Provider-.aspx

Below code will count online users

C# Code

MembershipUserCollection uc = Membership.GetAllUsers();

    int count=0; 
  foreach(MembershipUser u in uc)
  {
     if(u.IsOnline)
      count++;
  }

VB Code

Dim uc As MembershipUserCollection = Membership.GetAllUsers()
Dim count As Integer = 0
For Each u As MembershipUser In uc
    If u.IsOnline Then
        count += 1
    End If
Next

You can bind the online user names to ListBox using below code

C# code

System.Collections.Generic.List<string> lstUser = new System.Collections.Generic.List<string>();

        MembershipUserCollection uc = Membership.GetAllUsers();
       
        foreach (MembershipUser u in uc)
        {
            if (u.IsOnline)
               
                lstUser.Add(u.UserName);

        }

        ListBox1.DataSource = lstUser;
        ListBox1.DataBind();

VB code

 System.Collections.Generic.List<string> lstUser = new System.Collections.Generic.List<string>();

        MembershipUserCollection uc = Membership.GetAllUsers();
       
        foreach (MembershipUser u in uc)
        {
            if (u.IsOnline)
               
                lstUser.Add(u.UserName);

        }

        ListBox1.DataSource = lstUser;
        ListBox1.DataBind();

Satalaj