This is a code snippet which i got from Jeffrey Richters blog. This code offers a way to raise notification event when a garbage collection occurs on Generation 0 or Generation 2 object.

 Here is the code for the class:

public static class GCNotification {
   private static Action<Int32> s_gcDone = null; // The event’s field
   public static event Action<Int32> GCDone {
      add {
         // If there were no registered delegates before, start reporting notifications now 
         if (s_gcDone == null) { new GenObject(0); new GenObject(2); }
         s_gcDone += value;
      }
      remove { s_gcDone -= value; }
   }
   private sealed class GenObject {
      private Int32 m_generation;
      public GenObject(Int32 generation) { m_generation = generation; }
      ~GenObject() { // This is the Finalize method
         // If this object is in the generation we want (or higher), 
         // notify the delegates that a GC just completed
         if (GC.GetGeneration(this) >= m_generation) {
            Action<Int32> temp = Interlocked.CompareExchange(ref s_gcDone, null, null);
            if (temp != null) temp(m_generation);
         }
         // Keep reporting notifications if there is at least one delegate
         // registered, the AppDomain isn't unloading, and the process 
         // isn’t shutting down
         if ((s_gcDone != null) && 
            !AppDomain.CurrentDomain.IsFinalizingForUnload() && 
            !Environment.HasShutdownStarted) {
            // For Gen 0, create a new object; for Gen 2, resurrect the
            // object & let the GC call Finalize again the next time Gen 2 is GC'd
            if (m_generation == 0) new GenObject(0);
            else GC.ReRegisterForFinalize(this);
         } else { /* Let the objects go away */ }
      }
   }
}

public static void Main() {
   GCNotification.GCDone += g => Console.Beep(g == 0 ? 800 : 8000, 200);
   var l = new List<Object>();
   // Construct a lot of 100-byte objects.
   for (Int32 x = 0; x < 1000000; x++) {
      Console.WriteLine(x);
      Byte[] b = new Byte[100];
      l.Add(b);
   }
}