private void UpdateWindow()
        {
            int n_flagged = 0;

            for (int i = 0; i < flagged.GetLength(0); i++)
            {
                for (int j = 0; j < flagged.GetLength(1); j++)
                {
                    if (flagged[i, j] == true)
                    {
                        n_flagged++;
                    }
                }
            }
            NUMBER_MINES.Text = Convert.ToString(game.GetNumberMines() - n_flagged);

            for (int i = 0; i < game.GetRows(); i++)
            {
                for (int j = 0; j < game.GetCols(); j++)
                {
                    if (game.GetField()[i, j].IsOpen() == false)
                    {
                        if (flagged[i, j] == true)
                        {
                            buttons[i, j].Content = "\uD83C\uDFF3";

                            //buttons[i, j].Background = System.Windows.Media.Brushes.Green;
                            buttons[i, j].FontWeight = FontWeights.Bold;
                        }
                        else
                        {
                            buttons[i, j].Content    = "";
                            buttons[i, j].Background = System.Windows.Media.Brushes.DarkGray;
                        }
                    }
                    else if (game.GetField()[i, j].IsMine() == true)
                    {
                        buttons[i, j].Content    = "\uD83D\uDCA3";
                        buttons[i, j].FontSize   = 20.0;
                        buttons[i, j].Background = System.Windows.Media.Brushes.Red;
                        buttons[i, j].FontWeight = FontWeights.Bold;
                    }
                    else
                    {
                        int nM = game.GetField()[i, j].GetNNeighbouringMines();
                        buttons[i, j].Content    = (nM > 0) ? Convert.ToString(nM) : "";
                        buttons[i, j].Foreground = colors[nM];
                        buttons[i, j].Background = System.Windows.Media.Brushes.LightGray;
                        buttons[i, j].FontSize   = 20.0;
                        buttons[i, j].FontWeight = FontWeights.Bold;
                    }
                }
            }
        }