Windows Forms Application Documents (edit)

http://tripous.sourceforge.net/CSharp_WindowsForms.html

https://csharphardcoreprogramming.wordpress.com/tag/windows/

Cấu hình nâng cao về ngày tháng năm, số trong Windows

https://www.codeproject.com/Articles/205585/A-Csharp-WPF-NET-NumberBox-UserControl

https://www.experts-exchange.com/questions/23280981/Format-number-in-TextBox-when-typing.html

https://ourcodeworld.com/articles/read/507/how-to-allow-only-numbers-inside-a-textbox-in-winforms-c-sharp

How to format a windows forms Textbox with thousand separator and decimal separtor for Numeric input

Set up dot instead of comma in numeric values

Extended Textbox

Textbox display formatting

        private void textBox1_KeyUp(object sender, KeyEventArgs e)
        {
            if ((e.KeyCode == Keys.Right)
                || (e.KeyCode == Keys.Left)
                || (e.KeyCode == Keys.Up)
                || (e.KeyCode == Keys.Down))
            {
                // Do nothing
            }
            else
            {
                if (!string.IsNullOrEmpty(textBox1.Text))
                {
                    System.Globalization.CultureInfo culture = new System.Globalization.CultureInfo("vi-VN");
                    var valueBefore = decimal.Parse(textBox1.Text.Replace(".", ""), System.Globalization.NumberStyles.AllowThousands);
                    textBox1.Text = String.Format(culture, "{0:N0}", valueBefore);
                    textBox1.Select(textBox1.Text.Length, 0);
                }
            }
        }