[移动开发]winform中文本框限制只能输入数字和字母，退格键

正则表达式

        public bool RegexName(string str)
        {
            bool res = false;
            Regex reg = new Regex("^[a-zA-Z_0-9]+$");
            if (reg.IsMatch(str))
            {
                res = true;
            }
            return res;
        }

winform中文本框限制只能输入数字和字母

        private void txtSN_KeyPress(object sender, KeyPressEventArgs e)
        {
            if ((e.KeyChar >= 'a' && e.KeyChar <= 'z') || (e.KeyChar >= 'A' && e.KeyChar <= 'Z')
                || (e.KeyChar >= '0' && e.KeyChar <= '9') )
            {
                e.Handled = false;
            }
            else
            {
                e.Handled = true;
            }
        }