C#

using System;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        System.Timers.Timer timer;
        public Form1()
        {
            InitializeComponent();
            timer = new System.Timers.Timer();
            timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
            timer.Start();
        }

        void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            /* System.InvalidOperationException "Cross-thread operation not valid..."
            will be thrown if you try to alter the property directly from a different thread */
            if (this.InvokeRequired)
            {
                BeginInvoke(new MethodInvoker(delegate() { UpdateText(sender, e); }));
            }
            else
            {
                UpdateText(sender, e);
            }
        }
        private void UpdateText(object sender, System.Timers.ElapsedEventArgs e)
        {
            Text = e.SignalTime.ToString();
        }
    }
}

enum sample
    {
    Hello = 0,
    There,
    Last
    }

static void Main(string[] args)
    {
    for (sample t = 0; t < sample.Last; t++)
        {
        Console.WriteLine(t);
        }
    Console.WriteLine("---");
    }

List<string> list = new List<string>();
FieldInfo[] fis = type.GetFields(BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy);
foreach (FieldInfo fi in fis)
{
  if (fi.IsLiteral && !fi.IsInitOnly)
    list.Add(fi.Name);
}
return list;

Public Class Class1
    Public Const c1 As String = "c1"
    Public Const c2 As String = "c2"
    Const c3 As String = "c3"
    Dim var1 As String
    Public var2 As String

    Public Enum myEnum
        value1
        value2
    End Enum

End Class

For Each field As FieldInfo In getConstants(GetType(Class1))
            Console.WriteLine(field.Name)
Next

Private Function getConstants(ByVal pType As System.Type) As List(Of System.Reflection.FieldInfo)
        Dim fis() As FieldInfo
        Dim result As New List(Of System.Reflection.FieldInfo)

        fis = pType.GetFields()

        For Each fi As FieldInfo In fis
            If fi.IsLiteral And Not fi.IsInitOnly Then
                result.Add(fi)
            End If
        Next

        Return result

    End Function