IOS通讯录分区section汉字转拼音截取首字母

//汉字转拼音之后，截取首字母，并大写
-(NSString *)transformCharacter:(NSString*)sourceStr
{
    //先将原字符串转换为可变字符串
    NSMutableString *ms = [NSMutableString stringWithString:sourceStr];
    
    if (ms.length) {
        //将汉字转换为拼音
        CFStringTransform((__bridge CFMutableStringRef)ms, 0, kCFStringTransformToLatin, NO);
        //将拼音的声调去掉
        CFStringTransform((__bridge CFMutableStringRef)ms, 0,kCFStringTransformStripDiacritics,NO);
        //将字符串所有字母大写
        NSString *upStr = [ms uppercaseString];
        //截取首字母
        NSString *firstStr = [upStr substringToIndex:1];
        return firstStr;
    }
    return @"#";
}