Textbox display formatting

Question

I want to add \",\" to after every group of 3 digits. Eg : when I type 3000000 the textbox will display 3,000,000 but the value still is 3000000.
I tried to use maskedte

Answer 1

You could hook up to OnKeyUp event like this:

 private void textBox1_KeyUp(object sender, KeyEventArgs e)
        {
            if (!(e.KeyCode == Keys.Back))
            {
                string text = textBox1.Text.Replace(",", "");
                if (text.Length % 3 == 0)
                {
                    textBox1.Text += ",";
                    textBox1.SelectionStart = textBox1.Text.Length;
                }
            }
        }