Unicode解码、URL编码/解码

+ (NSString *) stringByReplaceUnicode:(NSString *)string
{
    NSMutableString *convertedString = [string mutableCopy];
    [convertedString replaceOccurrencesOfString:@"\U" withString:@"\u" options:0 range:NSMakeRange(0, convertedString.length)];
    CFStringRef transform = CFSTR("Any-Hex/Java");
    CFStringTransform((__bridge CFMutableStringRef)convertedString, NULL, transform, YES);
    return convertedString;
}
-(NSString *)URLEncodedString
{
    NSString *encodedString = (NSString *)
    CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                                              (CFStringRef)self,
                                                              NULL,
                                                              (CFStringRef)@"!*'();:@&=+$,/?%#[]",
                                                              kCFStringEncodingUTF8));
    return encodedString;
}
-(NSString *)URLDecodedString
{
    NSString *decodedString=(__bridge_transfer NSString *)CFURLCreateStringByReplacingPercentEscapesUsingEncoding(NULL, (__bridge CFStringRef)self, CFSTR(""), CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
    return decodedString;
}