public event EventHandler <MyTCEventArgs> Elapsed;           // Event declaration
 private void OnOneSecond(object obj, EventArgs e)
 {
     if (Elapsed != null)
     {
         MyTCEventArgs mtcea =
             new MyTCEventArgs("Message from OnOneSecond");
         Elapsed(obj, mtcea);
     }
 }
 public void TimerHandlerA(object obj, MyTCEventArgs e)
 {
     Console.WriteLine("Class A Message: {0}", e.Message);
 }