汉字换成拼音码

public static string GetChinesePell(string chinese)
        {
            string tempChar = "";
            char[] temp = chinese.ToCharArray();
            for (int i = 0; i < temp.Length; i++)
            {
                byte[] arrCN = Encoding.Default.GetBytes(temp[i].ToString());
                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 j = 0; j < 26; j++)
                    {
                        int max = 55290;
                        if (j != 25) max = areacode[j + 1];
                        if (areacode[j] <= code && code < max)
                        {
                            tempChar += Encoding.Default.GetString(new byte[] { (byte)(65 + j) }).ToLower();
                        }
                    }
                }
                else
                {
                    tempChar += temp[i];
                }
            }
            return tempChar;
        }