iOS获取/删除url中的参数

1.获取URL中的某个参数：

- (NSString *)getParameter:(NSString *)parameter urlStr:(NSString *)url {

    NSError *error;

    if (!url) {

        return@"";

    }

    NSString *regTags = [[NSString alloc] initWithFormat:@"(^|&|\\?)+%@=+([^&]*)(&|$)",parameter];

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

    NSArray *matches = [regex matchesInString:url options:0 range:NSMakeRange(0, [url length])];

    for (NSTextCheckingResult *match in matches) {

        NSString *tagValue = [url substringWithRange:[match rangeAtIndex:2]]; //分组2所对应的串

        return tagValue;

    }

    return@"";

}

2.删除URL中的某个参数：

- (NSString *)deleteParameter:(NSString *)parameter WithOriginUrl:(NSString *)originUrl {

    NSString *finalStr = [NSString string];

    NSMutableString * mutStr = [NSMutableString stringWithString:originUrl];

    NSArray *strArray = [mutStr componentsSeparatedByString:parameter];

    NSMutableString *firstStr = [strArray objectAtIndex:0];

    NSMutableString *lastStr = [strArray lastObject];

    NSRange characterRange = [lastStr rangeOfString:@"&"];

    if (characterRange.location !=NSNotFound) {

        NSArray *lastArray = [lastStr componentsSeparatedByString:@"&"];

        NSMutableArray *mutArray = [NSMutableArray arrayWithArray:lastArray];

        [mutArray removeObjectAtIndex:0];

        NSString *modifiedStr = [mutArray componentsJoinedByString:@"&"];

        finalStr = [[strArray objectAtIndex:0]stringByAppendingString:modifiedStr];

    } else {

        //以‘?‘、‘&‘结尾
        finalStr = [firstStr substringToIndex:[firstStr length] -1];

    }

    return finalStr;

}