Admin.ServiceInfo.userCardID_KeyPress C# (CSharp) Метод

        private void userCardID_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar >= '0' && e.KeyChar <= '9' || e.KeyChar == '\b')
            {
                e.Handled = false;
            }
            else
                e.Handled = true;
        }