C# 全角半角字符互转

/// <summary>
        /// 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
        /// </summary>
        /// <param name="input">任意字符串</param>
        /// <returns>全角字符串</returns>
        public static String ToSBC(String input)
        {
            // 半角转全角：
            char[] c = input.ToCharArray();
            for (int i = ; i < c.Length; i++)
            {
                if (c[i] == )
                {
                    c[i] = (char);
                    continue;
                }
                if (c[i] < )
                    c[i] = (char)(c[i] + );
            }
            return new String(c);
        }

        /// <summary>
        /// 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
        /// </summary>
        /// <param name="input">任意字符串</param>
        /// <returns>半角字符串</returns>
        public static String ToDBC(String input)
        {
            char[] c = input.ToCharArray();
            for (int i = ; i < c.Length; i++)
            {
                if (c[i] == )
                {
                    c[i] = (char);
                    continue;
                }
                if (c[i] >  && c[i] < )
                    c[i] = (char)(c[i] - );
            }
            return new String(c);
        }