#pragma mark - 获取url特定的参数-(NSString *) jiexi:(NSString *)CS webaddress:(NSString *)webaddress{    NSError *error;    NSString *regTags=[[NSString alloc] initWithFormat:@"(^|&|\\?)+%@=+([^&]*)(&|$)",CS];    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regTags                                                                           options:NSRegularExpressionCaseInsensitive                                                                             error:&error];        // 执行匹配的过程    NSArray *matches = [regex matchesInString:webaddress                                      options:0                                        range:NSMakeRange(0, [webaddress length])];    for (NSTextCheckingResult *match in matches) {                NSString *tagValue = [webaddress substringWithRange:[match rangeAtIndex:2]];  // 分组2所对应的串        return tagValue;    }    return @"";}