拼音操作工具类，包括将字符串转换成拼音数组，将单个字符转换成拼音，将汉字转换成拼音，取汉字的首字母(默认是大写)等-Pinyin operating tools, including phonetic string into an array of single characters into pinyin, will be converted into phonetic characters, take the first letter of characters (default is up