关于全角转半角的方法[转]

代码 

/// <summary>
        /// 替换全角字符为半角
        /// </summary>
        /// <returns></returns>
        public static string ReplaceSBC2DBC(string input)
        {
            // 全角正则
            string pattern = @"[\uFF00-\uFFFF]";
            string result = Regex.Replace(input, pattern, new MatchEvaluator(delegate(Match match)
            {
                return ToDBC(match.Value);
            }), RegexOptions.Compiled | RegexOptions.IgnoreCase);

            return result;
        }

/// <summary>
        /// 转半角的函数(DBC case)
        /// </summary>
        /// <param name="input">任意字符串</param>
        /// <returns>半角字符串</returns>
        ///<remarks>
        ///全角空格为12288，半角空格为32
        ///其他字符半角(33-126)与全角(65281-65374)的对应关系是：均相差65248
        ///</remarks>
        public static string ToDBC(string input)
        {
            char[] c = input.ToCharArray();
            for (int i = 0; i < c.Length; i++)
            {
                if (c[i] == 12288)
                {
                    c[i] = (char)32;
                    continue;
                }
                if (c[i] > 65280 && c[i] < 65375)
                    c[i] = (char)(c[i] - 65248);
            }
            return new string(c);
        }