汉字提取首字母

public  class GetCNSpell
    {

            /// <summary>  
            /// 提取汉字首字母   
            /// <param name="strText">需要转换的字</param>  
            /// <returns>转换结果</returns>  
            public string GetChineseSpell(string strText)
            {
                int len = strText.Length;
                string myStr = "";
                for (int i = 0; i < len; i++)
                {
                    myStr += getSpell(strText.Substring(i, 1));
                }
                return myStr;
            }
            /// <summary>  
            /// 把提取的字母变成小写  
            /// </summary>  
            /// <param name="strText">需要转换的字符串</param>  
            /// <returns>转换结果</returns>  
            public string GetLowerChineseSpell(string strText)
            {
                return GetChineseSpell(strText).ToLower();
            }
            /// <summary>  
            /// 把提取的字母变成大写  
            /// </summary>  
            /// <param name="myChar">需要转换的字符串</param>  
            /// <returns>转换结果</returns>  
            public string GetUpperChineseSpell(string strText)
            {
                return GetChineseSpell(strText).ToUpper();
            }
            /// <summary>  
            /// 获取单个汉字的首拼音  
            /// </summary>  
            /// <param name="myChar">需要转换的字符</param>  
            /// <returns>转换结果</returns>  
            public string getSpell(string myChar)
            {
                byte[] arrCN = System.Text.Encoding.Default.GetBytes(myChar);
                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 System.Text.Encoding.Default.GetString(new byte[] { (byte)(65 + i) });
                        }
                    }
                    return "_";
                }
                else return myChar;
            }
        }