EncodingHelper

        /// <summary>
        /// Url解码
        /// </summary>
        /// <param name="str">原始字符串</param>
        /// <param name="isuft8">是否utf8</param>
        /// <returns></returns>
        public static string Url2Str_(string Url, bool IsUTF8 = false)
        {
            string result = string.Empty;
            int len = Url.Length;
            ;
            int H, L;
            string Hex = "0123456789ABCDEF";
            List<byte> li = new List<byte>();
            while (i < len)
            {
                ) != "%")
                {
                    li.Add(Convert.ToByte(Url.Substring(i, )));
                }
                else
                {
                    i++;
                    H = Hex.IndexOf(Url.Substring(i, ).ToUpper());
                    i++;
                    L = Hex.IndexOf(Url.Substring(i, ).ToUpper());
                    li.Add(( + L));
                }
                i++;
            }

            if (IsUTF8 == true)
            {
                result = Encoding.UTF8.GetString(li.ToArray());
            }
            else
            {
                result = Encoding.Default.GetString(li.ToArray());
            }
            return result;

        }
        /// <summary>
        /// Url编码
        /// </summary>
        /// <param name="str">原始字符串</param>
        /// <param name="isuft8">是否utf8</param>
        /// <returns></returns>
        public static string Str2Url_(string strCode, bool NoEncodNum = false, bool isuft8 = false)
        {
            StringBuilder sb = new StringBuilder();
            byte[] byStr;
            if (isuft8 == false)
            {
                byStr = System.Text.Encoding.Default.GetBytes(strCode);
            }
            else
            {
                byStr = System.Text.Encoding.UTF8.GetBytes(strCode);
            }
            System.Text.RegularExpressions.Regex regKey = new System.Text.RegularExpressions.Regex("^[A-Za-z0-9]+$");
            ; i < byStr.Length; i++)
            {
                string strBy = Convert.ToChar(byStr[i]).ToString();
                if (NoEncodNum == true)
                {
                    if (regKey.IsMatch(strBy))
                    {
                        //是字母或者数字则不进行转换
                        sb.Append(strBy);
                    }
                    else
                    {
                        sb.Append());
                    }
                }
                else
                {
                    sb.Append());
                }

            }
            return (sb.ToString());
        }

        /// <summary>
        /// Url编码,encoding默认为utf8编码
        /// </summary>
        /// <param name="str">需要编码的字符串</param>
        /// <param name="encoding">指定编码类型</param>
        /// <returns>编码后的字符串</returns>
        public static string Str2Url(string str, Encoding encoding = null)
        {
            if (encoding == null)
            {
                return System.Web.HttpUtility.UrlEncode(str, Encoding.UTF8);
            }
            else
            {
                return System.Web.HttpUtility.UrlEncode(str, encoding);
            }
        }
        /// <summary>
        /// Url解码,encoding默认为utf8编码
        /// </summary>
        /// <param name="str">需要解码的字符串</param>
        /// <param name="encoding">指定解码类型</param>
        /// <returns>解码后的字符串</returns>
        public static string Url2Str(string str, Encoding encoding = null)
        {
            if (encoding == null)
            {
                return System.Web.HttpUtility.UrlDecode(str, Encoding.UTF8);
            }
            else
            {
                return System.Web.HttpUtility.UrlDecode(str, encoding);
            }
        }

        /// <summary>
        ///_usc2到ansi
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static string Unicode2StringEX(string str)
        {
            return HttpUtility.UrlDecode(Regex.Unescape(str));
        }
        /// <summary>
        /// 到ansi到usc2
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string Str2Unicode(string str)
        {
            return HttpUtility.UrlEncodeUnicode(str);
        }

        /// <summary>
        /// UTF8到GB2312
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string UTF82Str(string str)
        {
            string result = str;
            byte[] byteArray = System.Text.Encoding.UTF8.GetBytes(str);
            result = System.Text.Encoding.Default.GetString(byteArray, , byteArray.Length);
            return result;
        }
        /// <summary>
        /// GB2312到UTF8
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string Str2UTF8(string str)
        {
            string result = str;
            byte[] byteArray = System.Text.Encoding.Default.GetBytes(str);
            result = System.Text.Encoding.UTF8.GetString(byteArray, , byteArray.Length);
            return result;
        }

        /// <summary>
        /// 将字符串转换为base64格式 默认UTF8编码
        /// </summary>
        /// <param name="str">原始字符串</param>
        /// <param name="encoding">编码</param>
        /// <returns></returns>
        public static string String2Base64(string str, Encoding encoding = null)
        {
            if (encoding == null)
            {
                encoding = Encoding.UTF8;
            }
            return Convert.ToBase64String(encoding.GetBytes(str));
        }
        /// <summary>
        /// base64字符串转换为普通格式 默认UTF8编码
        /// </summary>
        /// <param name="str">原始字符串</param>
        /// <param name="encoding">编码</param>
        /// <returns></returns>
        public static string Base642String(string str, Encoding encoding = null)
        {
            if (encoding == null)
            {
                encoding = Encoding.UTF8;
            }
            byte[] buffer = Convert.FromBase64String(str);
            return encoding.GetString(buffer);
        }