SiteFactory 通用程序集中(PowerEasy.Common)的常用字符串处理函数

   以下是常用字符处理类StringHelper的各方法,这里给方法添加了简单的注释
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       /// <summary>
       /// 使用逗号分割符,扩充字符串
       /// </summary>
       /// <param name="sb"></param>
       /// <param name="append"></param>
        public static void AppendString(StringBuilder sb, string append)
        {
            AppendString(sb, append, ",");
        }
       /// <summary>
        /// 使用分割符,扩充字符串
       /// </summary>
       /// <param name="sb"></param>
       /// <param name="append"></param>
       /// <param name="split"></param>
        public static void AppendString(StringBuilder sb, string append, string split)
        {
            if (sb.Length == 0)
            {
                sb.Append(append);
            }
            else
            {
                sb.Append(split);
                sb.Append(append);
            }
        }
       /// <summary>
       /// 从Base64字符串中还原字符串
       /// </summary>
       /// <param name="input"></param>
       /// <returns></returns>
        public static string Base64StringDecode(string input)
        {
            byte[] bytes = Convert.FromBase64String(input);
            return Encoding.UTF8.GetString(bytes);
        }
       /// <summary>
        /// 将字符串保存为Base64编码序列
       /// </summary>
       /// <param name="input"></param>
       /// <returns></returns>
        public static string Base64StringEncode(string input)
        {
            return Convert.ToBase64String(Encoding.UTF8.GetBytes(input));
        }

       /// <summary>
       /// 将使用long表示的Ip转换为字符串表示
       /// </summary>
       /// <param name="ip"></param>
       /// <returns></returns>
        public static string DecodeIP(long ip)
        {
            string[] strArray = new string[] { ((ip >> 0x18) & 0xffL).ToString(), ".", ((ip >> 0x10) & 0xffL).ToString(), ".", ((ip >> 8) & 0xffL).ToString(), ".", (ip & 0xffL).ToString() };
            return string.Concat(strArray);
        }

        /// <summary>
        /// 将使用字符串表示的IP转换为使用数字值
        /// </summary>
        /// <param name="sip"></param>
        /// <returns></returns>
        public static double EncodeIP(string sip)
        {
            if (string.IsNullOrEmpty(sip))
            {
                return 0.0;
            }
            string[] strArray = sip.Split(new char[] { '.' });
            long num = 0L;
            foreach (string str in strArray)
            {
                byte num2;
                if (byte.TryParse(str, out num2))
                {
                    num = (num << 8) | num2;
                }
                else
                {
                    return 0.0;
                }
            }
            return num;
        }

       /// <summary>
       /// 过滤标签,正则匹配时使用非贪婪模式
       /// </summary>
       /// <param name="conStr">待处理的文本数据</param>
       /// <param name="tagName">标签名称如,html,Script等</param>
       /// <param name="fType">过滤方式,可以取(1|2|3)
       /// 1:是单个标签如img等,
       /// 2:表示配对出现的标签如div等将清除此标签已经标签内的全部文本,
       /// 3:表示也是针对配对出现的标签,但是保留标签内的内容.
       /// </param>
       /// <returns></returns>
       public static string CollectionFilter(string conStr, string tagName, int fType)
       {
           string input = conStr;
           switch (fType)
           {
               case 1:
                   return Regex.Replace(input, "<" + tagName + "([^>])*>", "", RegexOptions.IgnoreCase);

               case 2:
                   return Regex.Replace(input, "<" + tagName + "([^>])*>.*?</" + tagName + "([^>])*>", "", RegexOptions.IgnoreCase);

               case 3:
                   return Regex.Replace(Regex.Replace(input, "<" + tagName + "([^>])*>", "", RegexOptions.IgnoreCase), "</" + tagName + "([^>])*>", "", RegexOptions.IgnoreCase);
           }
           return input;
       }
       /// <summary>
       /// 过滤指定的标签
       /// </summary>
       /// <param name="conStr">待过滤文本数据</param>
       /// <param name="filterItem">需要过滤的列表用","阁开如:Iframe,Object,Style,Script,Div</param>
       /// <returns></returns>
        public static string FilterScript(string conStr, string filterItem)
        {
            string str = conStr.Replace("\r", "{$Chr13}").Replace("\n", "{$Chr10}");
            string[] strArray = filterItem.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
            foreach (string str2 in strArray)
            {
                switch (str2)
                {
                    case "Iframe":
                        str = CollectionFilter(str, str2, 2);
                        break;

                    case "Object":
                        str = CollectionFilter(str, str2, 2);
                        break;

                    case "Script":
                        str = CollectionFilter(str, str2, 2);
                        break;

                    case "Style":
                        str = CollectionFilter(str, str2, 2);
                        break;

                    case "Div":
                        str = CollectionFilter(str, str2, 3);
                        break;

                    case "Span":
                        str = CollectionFilter(str, str2, 3);
                        break;

                    case "Table":
                        str = CollectionFilter(CollectionFilter(CollectionFilter(CollectionFilter(CollectionFilter(str, str2, 3), "Tbody", 3), "Tr", 3), "Td", 3), "Th", 3);
                        break;

                    case "Img":
                        str = CollectionFilter(str, str2, 1);
                        break;

                    case "Font":
                        str = CollectionFilter(str, str2, 3);
                        break;

                    case "A":
                        str = CollectionFilter(str, str2, 3);
                        break;

                    case "Html":
                        str = StripTags(str);
                        goto Label_0218;
                }
            }
        Label_0218:
            return str.Replace("{$Chr13}", "\r").Replace("{$Chr10}", "\n");
        }

        public static bool FoundCharInArr(string checkStr, string findStr)
        {
            return FoundCharInArr(checkStr, findStr, ",");
        }

        public static bool FoundCharInArr(string checkStr, string findStr, string split)
        {
            bool flag = false;
            if (string.IsNullOrEmpty(split))
            {
                split = ",";
            }
            if (string.IsNullOrEmpty(checkStr))
            {
                return false;
            }
            if (checkStr.IndexOf(split) != -1)
            {
                string[] strArray;
                if (findStr.IndexOf(split) != -1)
                {
                    strArray = checkStr.Split(new char[] { Convert.ToChar(split) });
                    string[] strArray2 = findStr.Split(new char[] { Convert.ToChar(split) });
                    foreach (string str in strArray)
                    {
                        foreach (string str2 in strArray2)
                        {
                            if (string.Compare(str, str2) == 0)
                            {
                                flag = true;
                                break;
                            }
                        }
                        if (flag)
                        {
                            return flag;
                        }
                    }
                    return flag;
                }
                strArray = checkStr.Split(new char[] { Convert.ToChar(split) });
                foreach (string str in strArray)
                {
                    if (string.Compare(str, findStr) == 0)
                    {
                        return true;
                    }
                }
                return flag;
            }
            if (string.Compare(checkStr, findStr) == 0)
            {
                flag = true;
            }
            return flag;
        }
       /// <summary>
       /// 在字符串序列中(使用分割符连接的)查找指定值
       /// </summary>
       /// <param name="checkStr"></param>
       /// <param name="findStr"></param>
       /// <param name="split"></param>
       /// <returns></returns>
        public static bool FoundInArr(string checkStr, string findStr, string split)
        {
            bool flag = false;
            if (checkStr.IndexOf(findStr) != -1)
            {
                string[] strArray = checkStr.Split(new string[] { split }, StringSplitOptions.RemoveEmptyEntries);
                foreach (string str in strArray)
                {
                    if (string.Compare(str, findStr) == 0)
                    {
                        return true;
                    }
                }
                return flag;
            }
            if (string.Compare(checkStr, findStr) == 0)
            {
                flag = true;
            }
            return flag;
        }
       /// <summary>
       /// 返回字符串首字符,如果字符串首字符是汉字则返回其拼音的第一个字符(A-Z)
       /// </summary>
       /// <param name="testTxt"></param>
       /// <returns></returns>
        private static string GetGbkX(string testTxt)
        {
            if (testTxt.CompareTo("吖") >= 0)
            {
                if (testTxt.CompareTo("八") < 0)
                {
                    return "A";
                }
                if (testTxt.CompareTo("嚓") < 0)
                {
                    return "B";
                }
                if (testTxt.CompareTo("咑") < 0)
                {
                    return "C";
                }
                if (testTxt.CompareTo("妸") < 0)
                {
                    return "D";
                }
                if (testTxt.CompareTo("发") < 0)
                {
                    return "E";
                }
                if (testTxt.CompareTo("旮") < 0)
                {
                    return "F";
                }
                if (testTxt.CompareTo("铪") < 0)
                {
                    return "G";
                }
                if (testTxt.CompareTo("讥") < 0)
                {
                    return "H";
                }
                if (testTxt.CompareTo("咔") < 0)
                {
                    return "J";
                }
                if (testTxt.CompareTo("垃") < 0)
                {
                    return "K";
                }
                if (testTxt.CompareTo("嘸") < 0)
                {
                    return "L";
                }
                if (testTxt.CompareTo("拏") < 0)
                {
                    return "M";
                }
                if (testTxt.CompareTo("噢") < 0)
                {
                    return "N";
                }
                if (testTxt.CompareTo("妑") < 0)
                {
                    return "O";
                }
                if (testTxt.CompareTo("七") < 0)
                {
                    return "P";
                }
                if (testTxt.CompareTo("亽") < 0)
                {
                    return "Q";
                }
                if (testTxt.CompareTo("仨") < 0)
                {
                    return "R";
                }
                if (testTxt.CompareTo("他") < 0)
                {
                    return "S";
                }
                if (testTxt.CompareTo("哇") < 0)
                {
                    return "T";
                }
                if (testTxt.CompareTo("夕") < 0)
                {
                    return "W";
                }
                if (testTxt.CompareTo("丫") < 0)
                {
                    return "X";
                }
                if (testTxt.CompareTo("帀") < 0)
                {
                    return "Y";
                }
                if (testTxt.CompareTo("咗") < 0)
                {
                    return "Z";
                }
            }
            return testTxt;
        }
       /// <summary>
       /// 返回字串的拼音首字母序列(字串中的英文直接返回)
       /// </summary>
       /// <param name="str"></param>
       /// <returns></returns>
        public static string GetInitial(string str)
        {
            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < str.Length; i++)
            {
                builder.Append(GetOneIndex(str.Substring(i, 1)));
            }
            return builder.ToString();
        }

        private static string GetOneIndex(string testTxt)
        {
            if ((Convert.ToChar(testTxt) >= '\0') && (Convert.ToChar(testTxt) < 'Ā'))
            {
                return testTxt;
            }
            return GetGbkX(testTxt);
        }
       /// <summary>
       /// 是否包含中文
       /// </summary>
       /// <param name="inputData"></param>
       /// <returns></returns>
        public static bool IsIncludeChinese(string inputData)
        {
            Regex regex = new Regex("[一-龥]");
            return regex.Match(inputData).Success;
        }
       /// <summary>
       /// 计算MD5散列
       /// </summary>
       /// <param name="input"></param>
       /// <returns></returns>
        public static string MD5(string input)
        {
            using (MD5CryptoServiceProvider provider = new MD5CryptoServiceProvider())
            {
                return BitConverter.ToString(provider.ComputeHash(Encoding.UTF8.GetBytes(input))).Replace("-", "").ToLower();
            }
        }

        public static int MD5D(string strText)
        {
            using (MD5CryptoServiceProvider provider = new MD5CryptoServiceProvider())
            {
                byte[] bytes = Encoding.Default.GetBytes(strText);
                bytes = provider.ComputeHash(bytes);
                StringBuilder builder = new StringBuilder();
                foreach (byte num in bytes)
                {
                    builder.Append(num.ToString("D").ToLower());
                }
                string input = builder.ToString();
                if (input.Length >= 9)
                {
                    input = "9" + input.Substring(1, 8);
                }
                else
                {
                    input = "9" + input;
                }
                provider.Clear();
                return CLng(input);
            }
        }
       private static int CLng(string input)
       {
           int num;
           int.TryParse(input, out num);
           return num;
       }

       /// <summary>
       /// 使用GB2312编码来计算字符号的MD5值,返回32位序列
       /// </summary>
       /// <param name="input"></param>
       /// <returns></returns>
        public static string MD5gb2312(string input)
        {
            using (MD5CryptoServiceProvider provider = new MD5CryptoServiceProvider())
            {
                return BitConverter.ToString(provider.ComputeHash(Encoding.GetEncoding("gb2312").GetBytes(input))).Replace("-", "").ToLower();
            }
        }

        public static string RemoveXss(string input)
        {
            string str;
            input = Regex.Replace(input, @"(&#*\w+)[\x00-\x20]+;", "$1;");
            input = Regex.Replace(input, "(&#x*[0-9A-F]+);*", "$1;", RegexOptions.IgnoreCase);
            input = Regex.Replace(input, "&(amp|lt|gt|nbsp|quot);", "&amp;$1;");
            input = HttpUtility.HtmlDecode(input);
            input = Regex.Replace(input, @"[\x00-\x08\x0b-\x0c\x0e-\x19]", "");
            input = Regex.Replace(input, "(<[^>]+[\\x00-\\x20\"'/])(on|xmlns)[^>]*>", "$1>", RegexOptions.IgnoreCase);
            input = Regex.Replace(input, "([a-z]*)[\\x00-\\x20]*=[\\x00-\\x20]*([`'\"]*)[\\x00-\\x20]*j[\\x00-\\x20]*a[\\x00-\\x20]*v[\\x00-\\x20]*a[\\x00-\\x20]*s[\\x00-\\x20]*c[\\x00-\\x20]*r[\\x00-\\x20]*i[\\x00-\\x20]*p[\\x00-\\x20]*t[\\x00-\\x20]*:", "$1=$2nojavascript...", RegexOptions.IgnoreCase);
            input = Regex.Replace(input, "([a-z]*)[\\x00-\\x20]*=[\\x00-\\x20]*([`'\"]*)[\\x00-\\x20]*v[\\x00-\\x20]*b[\\x00-\\x20]*s[\\x00-\\x20]*c[\\x00-\\x20]*r[\\x00-\\x20]*i[\\x00-\\x20]*p[\\x00-\\x20]*t[\\x00-\\x20]*:", "$1=$2novbscript...", RegexOptions.IgnoreCase);
            input = Regex.Replace(input, "(<[^>]+)style[\\x00-\\x20]*=[\\x00-\\x20]*([`'\"]*).*expression[\\x00-\\x20]*\\([^>]*>", "$1>", RegexOptions.IgnoreCase);
            input = Regex.Replace(input, "(<[^>]+)style[\\x00-\\x20]*=[\\x00-\\x20]*([`'\"]*).*behaviour[\\x00-\\x20]*\\([^>]*>", "$1>", RegexOptions.IgnoreCase);
            input = Regex.Replace(input, "(<[^>]+)style[\\x00-\\x20]*=[\\x00-\\x20]*([`'\"]*).*s[\\x00-\\x20]*c[\\x00-\\x20]*r[\\x00-\\x20]*i[\\x00-\\x20]*p[\\x00-\\x20]*t[\\x00-\\x20]*:*[^>]*>", "$1>", RegexOptions.IgnoreCase);
            input = Regex.Replace(input, @"</*\w+:\w[^>]*>", "");
            do
            {
                str = input;
                input = Regex.Replace(input, "</*(applet|meta|xml|blink|link|style|script|embed|object|iframe|frame|frameset|ilayer|layer|bgsound|title|base)[^>]*>", "", RegexOptions.IgnoreCase);
            }
            while (str != input);
            return input;
        }
        /// <summary>
        /// 不区分大小写来替换字符串
        /// </summary>
        /// <param name="input"></param>
        /// <param name="oldValue"></param>
        /// <param name="newValue"></param>
        /// <returns></returns>
        public static string ReplaceIgnoreCase(string input, string oldValue, string newValue)
        {
            return Strings.Replace(input, oldValue, newValue, 1, -1, CompareMethod.Text);
        }
       /// <summary>
       /// 使用SHA1计算字符串的散列值
       /// </summary>
       /// <param name="input"></param>
       /// <returns></returns>
        public static string SHA1(string input)
        {
            using (SHA1CryptoServiceProvider provider = new SHA1CryptoServiceProvider())
            {
                return BitConverter.ToString(provider.ComputeHash(Encoding.UTF8.GetBytes(input))).Replace("-", "").ToLower();
            }
        }
       /// <summary>
       /// 过滤使用使用尖括号括起来的标签,不包括全部HTML定义如(&nbsp;等实体)
       /// </summary>
       /// <param name="input"></param>
       /// <returns></returns>
        public static string StripTags(string input)
        {
            Regex regex = new Regex("<([^<]|\n)+?>");
            return regex.Replace(input, "");
        }
       /// <summary>
       /// 按汉字计2,其他字符计1来取指定长度字符号串
       /// </summary>
       /// <param name="demand">需要截断的字符串</param>
       /// <param name="length">需要的长度</param>
       /// <param name="substitute">省略后替代的字符如:"..."等</param>
       /// <returns></returns>
        public static string SubString(string demand, int length, string substitute)
        {
            if (Encoding.Default.GetBytes(demand).Length <= length)
            {
                return demand;
            }
            ASCIIEncoding encoding = new ASCIIEncoding();
            length -= Encoding.Default.GetBytes(substitute).Length;
            int num = 0;
            StringBuilder builder = new StringBuilder();
            byte[] bytes = encoding.GetBytes(demand);
            for (int i = 0; i < bytes.Length; i++)
            {
                if (bytes[i] == 0x3f)
                {
                    num += 2;
                }
                else
                {
                    num++;
                }
                if (num > length)
                {
                    break;
                }
                builder.Append(demand.Substring(i, 1));
            }
            builder.Append(substitute);
            return builder.ToString();
        }
       /// <summary>
       /// 返回字串长度,中文字符为计2,其他计1
       /// 使用ASCII将字符串转化为字节数组时(byte[]),数组长度跟字符串长度相同
       /// 非中文字符取其ASCII码,中文ASCII码为63即?(十六进制为0x3F)
       /// </summary>
       /// <param name="strValue"></param>
       /// <returns></returns>
        public static int StringLength(string strValue)
        {
            if (string.IsNullOrEmpty(strValue))
            {
                return 0;
            }
            int num = 0;
            byte[] bytes = Encoding.ASCII.GetBytes(strValue);
            for (int i = 0; i < bytes.Length; i++)
            {
                if (bytes[i] == 0x3f)
                {
                    num += 2;
                }
                else
                {
                    num++;
                }
            }
            return num;
        }
       /// <summary>
       /// 去除字串两边的空格,当字串为Null Or Empty时,返回 String.Empty
       /// </summary>
       /// <param name="returnStr"></param>
       /// <returns></returns>
        public static string Trim(string returnStr)
        {
            if (!string.IsNullOrEmpty(returnStr))
            {
                return returnStr.Trim();
            }
            return string.Empty;
        }
        /// <summary>
        /// 将传入的password参数与md5Value参数进行比较(分别截取md5Valude的16位与32位)
        /// </summary>
        /// <param name="password">MD5后的哈希值</param>
        /// <param name="md5Value">MD5后的哈希值</param>
        /// <returns></returns>
        public static bool ValidateMD5(string password, string md5Value)
        {
            return ((string.Compare(password, md5Value) == 0) || (string.Compare(password, md5Value.Substring(8, 0x10)) == 0));
        }