DotNet的字元轉義操作

標籤：.net   c#   字元轉義   

  在項目中使用到字元的轉義，現在提供一種字元轉義和反轉義的操作方法：

1.轉義符操作：

        /// <summary>        /// 轉義符操作        /// </summary>        /// <param name="s"></param>        /// <param name="charToEliminate"></param>        /// <returns></returns>        public static string EscapeChar(string s, char charToEliminate)        {            char escapeChar;            char substituteChar;            GetEscapeAndEncodingChars(charToEliminate, out escapeChar, out substituteChar);            int i;            for (i = 0; i < s.Length; i++)            {                if (s[i] == charToEliminate || s[i] == escapeChar)                {                    break;                }            }            if (i == s.Length)            {                return s;            }            var sb = new StringBuilder(s.Substring(0, i), s.Length + 16);            for (; i < s.Length; i++)            {                var c = s[i];                if (c == charToEliminate)                {                    sb.Append(escapeChar);                    sb.Append(substituteChar);                }                else if (c == escapeChar)                {                    sb.Append(escapeChar, 2);                }                else                {                    sb.Append(c);                }            }            return sb.ToString();        }

2.反轉義符操作：

        /// <summary>        /// 反轉義符操作        /// </summary>        /// <param name="s"></param>        /// <param name="eliminatedChar"></param>        /// <returns></returns>        public static string UnescapeChar(string s, char eliminatedChar)        {            ArgumentValidator.ThrowIfNull(s, "s");            char escapeChar;            char substituteChar;            GetEscapeAndEncodingChars(eliminatedChar, out escapeChar, out substituteChar);            if (-1 == s.IndexOf(escapeChar))            {                return s;            }            var sb = new StringBuilder(s.Length);            for (var i = 0; i < s.Length; i++)            {                var c = s[i];                var next = i + 1;                if (c != escapeChar || next == s.Length)                {                    sb.Append(c);                    continue;                }                if (s[next] == escapeChar)                {                    sb.Append(escapeChar);                    i++;                }                else if (s[next] == substituteChar)                {                    sb.Append(eliminatedChar);                    i++;                }                else                {                    var msg = ("Invalid escaped string ‘{0}‘. Position {1} has escape character, but it is not followed by "                        + "another escape character or by the substitute character").Fi(s, i);                    throw new AssertionViolationException(msg);                }            }            return sb.ToString();        }

3.擷取轉義符和編碼字元：

        /// <summary>        /// 擷取轉義符和編碼字元        /// </summary>        /// <param name="charToEliminate"></param>        /// <param name="escapeChar"></param>        /// <param name="encodingChar"></param>        private static void GetEscapeAndEncodingChars(char charToEliminate, out char escapeChar, out char encodingChar)        {            var i = MEscapeChars[0] == charToEliminate ? 1 : 0;            escapeChar = MEscapeChars[i];            i++;            if (MEscapeChars[i] == charToEliminate)            {                i++;            }            encodingChar = MEscapeChars[i];        }

本文出自 “彭澤0902” 部落格，請務必保留此出處http://pengze0902.blog.51cto.com/7693836/1862764

DotNet的字元轉義操作