系统自带方法

NSString *hanziText = @"我是中国人";
    if ([hanziText length]) {
        NSMutableString *ms = [[NSMutableString alloc] initWithString:hanziText];
        if (CFStringTransform((__bridge CFMutableStringRef)ms, 0, kCFStringTransformMandarinLatin, NO)) {
            NSLog(@"带音标的pinyin: %@", ms);
            if (CFStringTransform((__bridge CFMutableStringRef)ms, 0, kCFStringTransformStripDiacritics, NO)) {
                     NSLog(@"不带音标的pinyin: %@", ms);
            }  
        }
    }