試圖解析XML

Question

我試圖解析以下XML文件：

然而，當我分析它：

-(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); 
    } 
} 

我得到以下的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網址沒有出現，並且有一堆空的網址。

爲什麼？

謝謝！

編輯：

我試圖藝術Fistman的答案，但我得到的是：

link is (null)

Answer 1

嘗試didStartElement回調。

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

當elementName是@"link"您的網址應該是attributeDict[@"href"]。

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

你會發現在didStartElement中啓動元素，所以在那裏改變狀態。當你找到字符時，檢查你是否處於正確的狀態，然後這些字符就是你想要的。

-(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"; 
    } 
}