C#

<pre lang="c#">
const string DEFAULT_CONNECTION_KEY = "defaultConnection";
ConnectionStringsSection section = (ConnectionStringsSection)config.GetSection("connectionStrings");
                    sConName = ConfigurationManager.AppSettings[DEFAULT_CONNECTION_KEY];
                    config.ConnectionStrings.ConnectionStrings[sConName].ConnectionString = sConCrypt;
config.Save(ConfigurationSaveMode.Full, true);
                    ConfigurationManager.RefreshSection("connectionStrings");

using System;
using System.Windows.Forms;

namespace Program
{

    public partial class Form1 : Form
    {     
        MySqlConnection cn = new MySqlConnection();
        iTextSharp.text.pdf.PdfWriter writer;

        const int panelHeight = 730;
        const int panelWith = 1070;
        private Label[,] lbs = new Label[70,50];
              

        public Form1()
        {
            InitializeComponent();
            initBoard();            
        }
       
        private void initBoard()
        {
            panel1.Size = new Size(panelWith, panelHeight);
            panel1.Visible = false;
            anel1.BackColor = SystemColors.ControlText;
        

            int cc, ff;
            for (int c = 0; c < 70; c++)
            {
                cc = c * 15;
                for (int f = 0; f < 50; f++)
                {
                    ff = f * 20;
                    Label lb = new Label();                    
                    lbs[c, f] = lb;                   
                    lb.Size = new Size(15, 20);
                    lb.Font = new System.Drawing.Font(label1.Font.Name, 12, FontStyle.Bold);                    
                    lb.Location = new System.Drawing.Point(cc + 10, ff + 10);
                    lb.Parent = panel1;
                    lb.ForeColor = Color.WhiteSmoke;
                }
            }

        }

        private void button1_Click(object sender, EventArgs e)
        {            
                        
            for (int c = 0; c < 70; c++)
                for (int f = 0; f < 50; f++)
                    lbs[c, f].Text =  (f % 10).ToString();

            panel1.Visible = true;

        }


    }
}

dgvScore.Rows.Clear(); // Clear previous entries ready for next button click
  dgvScore.RowHeadersVisible = false; // Remove headers not needed for showing high score
  //Set up Datagrid Headings
  dgvScore.ColumnCount = 2;
  dgvScore.Columns[0].Name = "Name";
  dgvScore.Columns[1].Name = "Score";
  //==========================================================
  // Try to add image
  DataGridViewImageColumn img = new DataGridViewImageColumn();
  img.Name = "img";
  img.HeaderText = "Image";
  img.ValuesAreIcons = true;
  Image image = (Bitmap)Properties.Resources.ResourceManager.GetObject("diceicon.ico");
  img.Image = image;
  dgvScore.Columns.Add(img);
  //======================================================

var MouseDown = Observable.FromEventPattern<MouseButtonEventArgs>(this, "MouseDown");
var MouseUp = Observable.FromEventPattern<MouseButtonEventArgs>(this, "MouseUp");

var LeftMouseButtonPressedDuration = Observable.Join(
                  MouseDown
                  .Where(evt => evt.EventArgs.ChangedButton == MouseButton.Left)
                  .Select(_ =>
                  {
                      DateTime now = DateTime.Now;
                      return now;
                  }
                  ),
                  MouseUp
                   .Where(evt => evt.EventArgs.ChangedButton == MouseButton.Left)
                   .Select(_ =>
                    {
                        DateTime now = DateTime.Now;
                        return now;
                    }
                    ),

                  MouseDownTimeStamp => MouseDown,
                  MouseUpTimeStamp => Observable.Empty<DateTime>(),

                  (TimeDown, TimeUp) =>
                  {
                      TimeSpan MousePressedDuration = TimeUp - TimeDown;
                      return " Total duartion is: " + MousePressedDuration.ToString(@"ss\:fff");
                  }
                );

LeftMouseButtonPressedDuration.Subscribe(evt =>
{
    txtMainWindow.Text += Environment.NewLine + evt.ToString();
});

MouseUpTimeStamp => Observable.Empty<DateTime>()

MouseDownTimeStamp => MouseDown.Publish(),
 MouseUpTimeStamp => Observable.Empty<DateTime>(),

var Interval_50ms = Observable.Interval(TimeSpan.FromMilliseconds(50))
    .Take(10);

var Interval_100ms = Observable.Interval(TimeSpan.FromMilliseconds(100))
    .Take(5)
    .Select(i => Convert.ToChar(i + 65).ToString().ToUpper());

var tt = Observable.Join(
    Interval_50ms,
    Interval_100ms,
    s => Interval_50ms,
    c => Observable.Empty<char>(),
    (s, c) => { return s.ToString() + ", " + c.ToString(); })
    .Subscribe(Console.WriteLine);

3, A
3, A
3, B
6, D
8, E

0, A
2, B
4, D
6, E