1、方法一：键和值一起替换

- (NSString *) paramValueOfUrl:(NSString *) url withParam:(NSString *) param value:(NSString *)value{
    
    NSError *error;

    NSString *targetString = [NSString stringWithFormat:@"%@=%@",param,value];

    NSString *regTags = [[NSString alloc] initWithFormat:@"%@=+([\\w]*)",param];

    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regTags options:0 error:&error];

    NSString *string = [regex stringByReplacingMatchesInString:url
                                                       options:0
                                                         range:NSMakeRange(0, [url length])
                                                  withTemplate:targetString];

    return string;
}

2、方法二： 值替换

/// 方法二：
- (NSString *) paramValueOfUrl2:(NSString *) url withParam:(NSString *) param value:(NSString *)value{

        NSError *error;
    
        //  (^|&|\\?|#)+%@=+([^&|#]*)(#|&|$) ： range 取 [match rangeAtIndex:2]
        //  %@=+([^&|#]*)(#|&|$)   ： range 取 [match rangeAtIndex:1]
        //  通过numberOfRanges获取结果数量，然后分别打印获取值 [url substringWithRange:[match rangeAtIndex:i]]
        NSString *regTags = [[NSString alloc] initWithFormat:@"(^|&|\\?|#)+%@=+([^&|#]*)(#|&|$)",param];
        NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regTags
                                                                               options:NSRegularExpressionCaseInsensitive
                                                                                 error:&error];
    
        // 执行匹配的过程
        NSArray *matches = [regex matchesInString:url
                                          options:0
                                            range:NSMakeRange(0, [url length])];
        for (NSTextCheckingResult *match in matches) {
            NSRange range = [match rangeAtIndex:2];
            NSString *tagValue = [url substringWithRange:range];  // 分组2所对应的串
            if (![value isEqualToString:tagValue]) {
                url = [url stringByReplacingCharactersInRange:range withString:value];
            }
        }
        return url;
}