ios Url Encode

//ios Url Encode 
//有時候在請求的參數里里特殊符號比如“+”等。而如果沒有encode的話那么傳過去的還是”  ”，面實際上是%2B。
-(NSString*)UrlValueEncode:(NSString*)str
{
        NSString *result = (NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                                                               (CFStringRef)str,
                                                                               NULL,
                                                                                  CFSTR("!*'();:@&=+$,/?%#[]"),
                                                                               kCFStringEncodingUTF8);
       [result autorelease];
       return result;
}



//- (NSString*)URLDecodedString:(NSString*)str
//{
////    NSString *result = [[self stringByReplacingOccurrencesOfString:@"%0D%0A" withString:@""] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
//    NSString *result = [[str stringByReplacingOccurrencesOfString:@"%0D%0A" withString:@""] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
//    return [result stringByReplacingOccurrencesOfString:@"+" withString:@" "];
//}