试图解析XML

Question

我试图解析以下XML文件：

​

​

但是，当我解析它时：

-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
    currentElementName = elementName;
}
-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
    if ([currentElementName isEqualToString:@"link"]) {
        NSLog(@"Link: %@",string);
    }
}

我得到了以下NSLOG：

 Link: http://www.flickr.com/photos/114014058@N06/
 Link: 

 Link: http://www.flickr.com/photos/114014058@N06/
 Link: 

 Link: 


 Link: http://www.flickr.com/photos/114014058@N06/11865861164/
 Link:

正如您所看到的，我想要的URL没有出现，并且有一堆空URL。

为什么？

谢谢!

编辑：

我尝试了有节奏的费斯曼的答案，但我得到的只是：

link is (null)

Answer 1

尝试didStartElement回调。

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict;

当elementName是@"link"时，您的url应该在attributeDict[@"href"]中。

例如：

    - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict {
        if([elementName isEqualToString:@"link"]) {
            NSLog(@"link is %@\n", attributeDict[@"href"]);
        }
    }

Answer 2

您将在didStartElement中找到元素，因此在那里更改状态。当您得到foundCharacters时，检查您是否处于正确的状态，然后那里的字符就是您想要的。

-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
    // assume currentElementName starts out nil.  if we find "generator", enter
    // "generator" state.  if we're in "generator" state and find "link" then enter
    // "link" state, which is our target state

    if ([currentElementName isEqualToString:@"generator"] && [elementName isEqualToString:@"link"])
        currentElementName = @"link";

        // now we're in the tag we want to be in.  get attributes from 
        // the attributeDict, if you need the tag body, check for "link" state in foundChars

        NSLog(@"here are the attributes we want %@", attributeDict);

    else if ([elementName isEqualToString:@"generator"]) {
        currentElementName = @"generator";
    }
}