c#取汉字拼音首字母

 

    /// <summary>
    /// GB2312的拼音算法，不支持多音字
    /// </summary>
    public class GB2Alpha
    {
        public static void GetAlpha(string a)
        {
            int aa = Convert.ToInt32(a[0]);
            byte[] arr = System.Text.Encoding.ASCII.GetBytes(a);
            char c = convert(aa);
        }
        //汉字首字母转换表
        private static char convert(int n)
        {
            if (In(0xB0A1, 0xB0C4, n)) return 'A';
            if (In(0XB0C5, 0XB2C0, n)) return 'B';
            if (In(0xB2C1, 0xB4ED, n)) return 'C';
            if (In(0xB4EE, 0xB6E9, n)) return 'D';
            if (In(0xB6EA, 0xB7A1, n)) return 'E';
            if (In(0xB7A2, 0xB8c0, n)) return 'F';
            if (In(0xB8C1, 0xB9FD, n)) return 'G';
            if (In(0xB9FE, 0xBBF6, n)) return 'H';
            if (In(0xBBF7, 0xBFA5, n)) return 'J';
            if (In(0xBFA6, 0xC0AB, n)) return 'K';
            if (In(0xC0AC, 0xC2E7, n)) return 'L';
            if (In(0xC2E8, 0xC4C2, n)) return 'M';
            if (In(0xC4C3, 0xC5B5, n)) return 'N';
            if (In(0xC5B6, 0xC5BD, n)) return 'O';
            if (In(0xC5BE, 0xC6D9, n)) return 'P';
            if (In(0xC6DA, 0xC8BA, n)) return 'Q';
            if (In(0xC8BB, 0xC8F5, n)) return 'R';
            if (In(0xC8F6, 0xCBF0, n)) return 'S';
            if (In(0xCBFA, 0xCDD9, n)) return 'T';
            if (In(0xCDDA, 0xCEF3, n)) return 'W';
            if (In(0xCEF4, 0xD188, n)) return 'X';
            if (In(0xD1B9, 0xD4D0, n)) return 'Y';
            if (In(0xD4D1, 0xD7F9, n)) return 'Z';
            return '\0';
        }
        private static bool In(int start, int end, int code)
        {
            if (code >= start && code <= end)
            {
                return true;
            }
            return false;
        }
    }

    /// <summary>
    /// 拼音首字母，支持多音字,
    /// ，确保pinyin3.txt中汉字编码是连续的，汉字编码减去MinChar就得到在数组中的index，从而避免了作循环检测的消耗，所以全角字母的检测放在代码里面而没有放在pinyin3.txt中
    /// </summary>
    public static class CSpell
    {
        private static int MinChar;

        private static int MaxChar;

        /// <summary>
        /// 确保pinyin3.txt中汉字编码是连续的,因为算法中要作减法运算
        /// </summary>
        private static string[] Lines;
        static bool init = false;
        /// <summary>
        /// 初始化
        /// </summary>
        internal static void Init()
        {
            if (init) return;
            init = true;
            Lines = Resource1.pinyin3.Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries);

            MinChar = (int)(Lines[0][0]);

            MaxChar = (int)(Lines[Lines.Length - 1][0]);
        }

        /// <summary>
        /// 检测，区分大小写，“浦发银行”=="YH"/"YX"
        /// </summary>
        public static bool HitTestSpell(string strOrigin, string strCompare)
        {
            string[][] arrStr = GetStringSpell(strOrigin);

            if (strCompare.Length > strOrigin.Length) return false;
            int index, beginIndex = 0;
            for (int i = 0; i < strCompare.Length; i++)
            {
                index = Find(arrStr, strCompare[i].ToString(), beginIndex);
                if (index < 0)
                {
                    return false;
                }
                else
                {
                    //如果多次找到的拼音不连续,则失败
                    if (beginIndex != 0 && beginIndex != index)
                        return false;
                    beginIndex = index + 1;
                }
            }

            return true;
        }

        /// <summary>
        /// 检测，区分大小写，“浦发银行”=="YH"/"YX"
        /// </summary>
        public static int HitTestSpellInt(string strOrigin, string strCompare)
        {
            string[][] arrStr = GetStringSpell(strOrigin);

            if (strCompare.Length > strOrigin.Length) return ErrCode.Fail;
            int index, beginIndex = 0;
            int firstIndex = -1;
            for (int i = 0; i < strCompare.Length; i++)
            {
                index = Find(arrStr, strCompare[i].ToString(), beginIndex);
                if (index < 0)
                {
                    return ErrCode.Fail;
                }
                else
                {
                    if (firstIndex < 0) firstIndex = index;
                    beginIndex = index + 1;
                }
            }

            return firstIndex;
        }

        private static int Find(string[][] arrStr, string chr, int beginIndex)
        {
            for (int i = beginIndex; i < arrStr.Length; i++)
            {
                if (ContainsChar(arrStr[i], chr))
                {
                    return i;
                }
            }
            return -1;
        }

        private static bool ContainsChar(string[] arrStr, string chr)
        {
            for (int i = 0; i < arrStr.Length; i++)
            {
                if (arrStr[i] == chr) return true;
            }
            return false;
        }

        /// <summary>
        /// 返回字符串的拼音
        /// </summary>
        public static string[][] GetStringSpell(string str)
        {
            string[][] arrStr = new string[str.Length][];
            for (int i = 0; i < str.Length; i++)
            {
                arrStr[i] = GetCharSpell(str[i]);
            }

            return arrStr;
        }

        /// <summary>
        /// 返回字符的拼音
        /// </summary>
        public static string[] GetCharSpell(char chr)
        {
            int nchar = (int)chr;
            if (nchar >= MinChar && nchar <= MaxChar)
            {
                string[] splitChars = Lines[nchar - MinChar].Split(' ');
                string[] result = new string[splitChars.Length - 1];
                for (int i = 1; i < splitChars.Length; i++)
                {
                    result[i - 1] = splitChars[i];
                }
                return result;
            }
            else
            {
                //全角字母：A-Z
                if (chr >= char_A_QuanJiao && chr <= char_Z_QuanJiao)
                {
                    string[] result = new string[1];

                    result[0] = ((char)(char_A + (chr - char_A_QuanJiao))).ToString();

                    return result;
                }
                else
                {
                    //不是汉字则直接返回该string
                    string[] result = new string[1];
                    result[0] = chr.ToString();
                    return result;
                }
            }
        }
        private const char char_A_QuanJiao = 'Ａ';
        private const char char_Z_QuanJiao = 'Ｚ';
        private const char char_A = 'A';
        private const char char_Z = 'Z';
    }

 

 

 

pinyin3.txt  下载拼音表