WinForms Textbox only allow numbers between 1 and 6

Question

I want to restrict my WinForms Textbox so it only allows numbers between 1 and 6 to be entered. No letters, no other symbols or special characters, just those numbers.

How do I do that?

Answer 1

Have you tried SupressKeyPress?

if (e.KeyCode < Keys.D1 || e.KeyCode > Keys.D6 || e.Shift || e.Alt)
        {
            e.SuppressKeyPress = true;
        }

        if (e.KeyCode == Keys.Back)
        {
            e.SuppressKeyPress = false;
        }

The 2nd If makes you able to press backspace if you want to change what you wrote.