//ios Url Encode //有时候在请求的参数里里特殊符号比如“+”等。而如果没有encode的话那么传过去的还是”  ”，面实际上是%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:@" "];//}