//汉字转拼音

    NSMutableString *mutableString = [NSMutableString stringWithString:person.name];

    CFStringTransform((CFMutableStringRef)mutableString, NULL, kCFStringTransformToLatin, false);

    mutableString = (NSMutableString *)[mutableString stringByFoldingWithOptions:NSDiacriticInsensitiveSearch locale:[NSLocale currentLocale]];

    

    //获取首字母, 并转成大写

    NSString *firstLetter = [[mutableString substringToIndex:1] uppercaseString];//从0 开始到 某个位置

    //uppercaseString转化成大写,lowercaseString转化成小写