汉字转拼音，中文拼音排序器

汉字转拼音

NSMutableString *ms = [[NSMutableString alloc] initWithString:@"我是中国人"];
if (CFStringTransform((__bridge CFMutableStringRef)ms, 0, kCFStringTransformMandarinLatin, NO)) {
    NSLog(@"Pingying: %@", ms); // wǒ shì zhōng guó rén
}
if (CFStringTransform((__bridge CFMutableStringRef)ms, 0, kCFStringTransformStripDiacritics, NO)) {
    NSLog(@"Pingying: %@", ms); // wo shi zhong guo ren
}

中文拼音排序器

#define GB18030_ENCODING CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000)
+ (NSComparator)compor {
  return ^NSComparisonResult(NSString *obj1, NSString *obj2) {
    NSString *str1 = [obj1 stringByAddingPercentEscapesUsingEncoding:GB18030_ENCODING];
    NSString *str2 = [obj2 stringByAddingPercentEscapesUsingEncoding:GB18030_ENCODING];
    return [str1 compare:str2];
  };
}

原理：中文gb编码本来就是用拼音排序的就hack了一下：在stringByAddingPercentEscapesUsingEncoding:后面用16位编码 将中文转为ascii来比较 更简洁。