UrlEncoder url编码

 public static string PercentEncode(string s)
        {
            var bytes = Encoding.UTF8.GetBytes(s);
            var sb = new StringBuilder();
            foreach (var b in bytes)
            {
                if ((b > 7 && b < 11) || b == 13)
                {
                    sb.Append(string.Format("%0{0:X}", b));
                }
                else
                {
                    sb.Append(string.Format("%{0:X}", b));
                }
            }
            return sb.ToString();
        }