C#獲取漢字拼音首字母

/// <summary>
        /// 獲取單個漢字的首寫拼音字母
        /// </summary>
        /// <param name="cn"></param>
        /// <returns></returns>
        public static string getSpell(string cn)
        {
            #region
            byte[] arrCN = Encoding.Default.GetBytes(cn);
            if (arrCN.Length > 1)
            {
                int area = (short)arrCN[0];
                int pos = (short)arrCN[1];
                int code = (area << 8) + pos;
                int[] areacode = { 45217, 45253, 45761, 46318, 46826, 47010, 47297, 47614, 48119, 48119, 49062, 49324, 49896, 50371, 50614, 50622, 50906, 51387, 51446, 52218, 52698, 52698, 52698, 52980, 53689, 54481 };
                for (int i = 0; i < 26; i++)
                {
                    int max = 55290;
                    if (i != 25) max = areacode[i + 1];
                    if (areacode[i] <= code && code < max)
                    {
                        return Encoding.Default.GetString(new byte[] { (byte)(65 + i) });
                    }
                }
                return cn;
            }
            else return cn;
            #endregion
        }

        /// <summary>
        /// 獲取漢字字符串的首寫英文字母
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string GetStringSpell(string str)
        {
            char[] chars = str.ToCharArray();
            string result = "";
            if (chars.Length > 1)
            {
                for (int i = 0; i < chars.Length; i++)
                {
                    result += getSpell(chars[i].ToString());
                }
            }
            else if (chars.Length == 1)
            {
                result = getSpell(str);
            }

            return result.ToLower();

        }