C#获得字符串首字符字母（大写）

        /// <summary>
        /// 获得字符串首字符字母（大写）；
        /// </summary>
        /// <param name="cnChar"></param>
        /// <returns></returns>
        public string GetStringFirstSpell(string cnChar)
        {
            //除字母、数字、汉字以外的返回"*"
            var result = "*";

            if (string.IsNullOrEmpty(cnChar.Trim()))
                return result;

            cnChar = cnChar.Trim().Substring(, );
            byte[] arrCn = Encoding.Default.GetBytes(cnChar);

            //首字为字符,占一个字节
            if (arrCn.Length <= )
            {
                //大写英文字母
                if ((short)arrCn[] >=  && (short)arrCn[] <= )
                    return cnChar;

                //小写英文字母
                if (arrCn[] >=  && arrCn[] <= )
                    return Encoding.Default.GetString(new byte[] { (byte)((short)arrCn[] - ) });

                //数字
                switch (cnChar)
                {
                    case "":
                        result = "Y";
                        break;
                    case "":
                        result = "E";
                        break;
                    case "":
                    case "":
                        result = "S";
                        break;
                    case "":
                        result = "W";
                        break;
                    case "":
                    case "":
                        result = "L";
                        break;
                    case "":
                        result = "Q";
                        break;
                    case "":
                        result = "B";
                        break;
                    case "":
                        result = "J";
                        break;
                }
                return result;
            }
            //首字为汉字,占两个字节
            else
            {
                int area = (short)arrCn[];
                int pos = (short)arrCn[];
                int code = (area << ) + pos;
                int[] areacode = { , , , , , , , , , , , , , , , , , , , , , , , , ,  };
                for (int i = ; i < ; i++)
                {
                    int max = ;
                    if (i != ) max = areacode[i + ];
                    if (areacode[i] <= code && code < max)
                    {
                        return Encoding.Default.GetString(new byte[] { (byte)( + i) });
                    }
                }
                return result;
            }
        }

有时候需要对汉字获取其拼音首字母，可以用以上的方法。