iOS:NSXMLParser获取属性

Question

我是新手,我正在尝试阅读RSS提要,到目前为止一切都很好.我是这样做的:

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
  if ([elementName isEqualToString:@"item"]) {
    [item setObject:currentTitle forKey:@"title"];
    [item setObject:currentLink forKey:@"link"];
    [item setObject:currentSummary forKey:@"summary"];
    [item setObject:currentDate forKey:@"date"];
    [item setObject:currentImage forKey:@"enclosure"];

    [stories addObject:[item copy]];
    NSLog(@"adding story: %@", currentTitle);
  }
}

问题在于圈地.在XML中看起来像这样:

<enclosure length="150" url="urltoimage.jpg" type="image/jpeg" />

如何从我的函数中获取该元素的url属性？

编辑 XML看起来像这样:

<item>
    <title>...</title>
    <link>...</link>
    <description>...</description>
    <pubDate>...</pubDate>
    <enclosure length="150" url="urltoimage.jpg" type="image/jpeg" />
</item>

我的foundCharacters函数看起来像这样:

- (void)parser: (NSXMLParser *)parser foundCharacters:(NSString *)string {
  if ([currentElement isEqualToString:@"title"]) {
    [currentTitle appendString:string];
  } else if ([currentElement isEqualToString:@"link"]) {
    [currentLink appendString:string];
  } else if ([currentElement isEqualToString:@"description"]) {
    [currentSummary appendString:string];
  } else if ([currentElement isEqualToString:@"pubDate"]) {
    [currentDate appendString:string];
  }
}

Answer 1

- (void)parser:(NSXMLParser *)parser
didStartElement:(NSString *)elementName
  namespaceURI:(NSString *)namespaceURI
 qualifiedName:(NSString *)qualifiedName
    attributes:(NSDictionary *)attributeDict
{
    // just do this for item elements
    if(![elementName isEqual:@"enclosure"])
        return;

    // then you just need to grab each of your attributes
    NSString * name = [attributeDict objectForKey:@"url"];

    // ... get the other attributes

    // when we have our various attributes, you can add them to your arrays
    [m_NameArray addObject:name];

    // ... same for the other arrays
}

Answer 2

您必须再处理一个回调以跟踪属性:

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

attributeDict 是包含所有找到的元素参数的字典