在两个XML标记之间提取文本的NSRegularExpression。

How to extract the value "6" between the "badgeCount" tags using NSRegularExpression. Following is the response from the server:

如何使用NSRegularExpression从“badgeCount”标记中提取值“6”。以下是服务器的回复:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><badgeCount>6</badgeCount><rank>2</rank><screenName>myName</screenName>

Following is the code I tried but not getting success. Actually it goes in else part and prints "Value of regex is nil":

下面是我尝试过的代码，但没有成功。实际上，它进入else部分并打印“regex的值为nil”:

NSString *responseString =   [[NSString alloc] initWithBytes:[responseDataForCrntUser bytes] length:responseDataForCrntUser.length encoding:NSUTF8StringEncoding];

NSError *error;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(?<=badgeCount>)(?:[^])*?(?=</badgeCount)" options:0 error:&error];
if (regex != nil) {
    NSTextCheckingResult *firstMatch = [regex firstMatchInString:responseString options:0 range:NSMakeRange(0, [responseString length])];
    NSLog(@"NOT NIL");
    if (firstMatch) {
        NSRange accessTokenRange = [firstMatch rangeAtIndex:1];
        NSString *value = [urlString substringWithRange:accessTokenRange];
        NSLog(@"Value: %@", value);
    }
}
else
    NSLog(@"Value of regex is nil");

If you could provide sample code that would be much appreciated.

如果您能提供样例代码，我们将不胜感激。

NOTE: I don't want to use NSXMLParser.

注意:我不想使用NSXMLParser。

2 个解决方案

#1

Example:

例子:

NSString *xml = @"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><badgeCount>6</badgeCount><rank>2</rank><screenName>myName</screenName>";
NSString *pattern = @"<badgeCount>(\\d+)</badgeCount>";

NSRegularExpression *regex = [NSRegularExpression
                                      regularExpressionWithPattern:pattern
                                      options:NSRegularExpressionCaseInsensitive
                                      error:nil];
NSTextCheckingResult *textCheckingResult = [regex firstMatchInString:xml options:0 range:NSMakeRange(0, xml.length)];

NSRange matchRange = [textCheckingResult rangeAtIndex:1];
NSString *match = [xml substringWithRange:matchRange];
NSLog(@"Found string '%@'", match);

NSLog output:

NSLog输出:

Found string '6'

#2

To do it in swift 3.0

要在swift 3.0中做到这一点

func getMatchingValueFrom(strXML:String, tag:String) -> String {
    let pattern : String = "<"+tag+">(\\d+)</"+tag+">"
    let regexOptions = NSRegularExpression.Options.caseInsensitive

    do {
        let regex = try NSRegularExpression(pattern: pattern, options: regexOptions)
        let textCheckingResult : NSTextCheckingResult = regex.firstMatch(in: strXML, options: NSRegularExpression.MatchingOptions(rawValue: UInt(0)), range: NSMakeRange(0, strXML.characters.count))!
        let matchRange : NSRange = textCheckingResult.rangeAt(1)
        let match : String = (strXML as NSString).substring(with: matchRange)
        return match
    } catch {
        print(pattern + "<-- not found in string -->" + strXML )
        return ""
    }
}

P.S : This is corresponding swift solution of @zaph's solution in obj-c

P。S:这是在object -c中@zaph的快速解决方案

#1