MainWindow.cs

public MainWindow()
{
  InitializeComponent();
  // Logea las excepciones no controladas.
  AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(unhandledException);
}

static void unhandledException(object sender, UnhandledExceptionEventArgs args)
{
  Exception e = (Exception)args.ExceptionObject;
  Console.WriteLine("MyHandler caught : " + e.Message);
  Console.WriteLine("Runtime terminating: {0}", args.IsTerminating);
  Console.WriteLine("StackTrace: {0}", e.StackTrace);

  using (System.IO.StreamWriter file = new System.IO.StreamWriter(Directory.GetCurrentDirectory() + @"\log.txt", true))
  {
    DateTimeOffset date = DateTimeOffset.Now;
    file.WriteLine("========={0:MM/dd/yy H:mm:ss zzz}=========", date);
    file.WriteLine(e.Message);
    file.WriteLine(args.IsTerminating);
    file.WriteLine(e.StackTrace);
  }
}