我无法理解NSXMLParser。我尝试了一些外部XML解析器,但我没有运气。我想要做的是解析GDATA Youtube API xml,它检索视频的xml。这工作正常我有xml但很难通过元素重复。我只需要一个可以检索元素的示例,例如(media:thumbnail url =“”)(/ media:thumbnail)
如何从元素媒体获取url值:thumbnail
答案 0 :(得分:0)
这是您使用NSXMLParser
:
在.h文件中声明:
NSMutableData *webPortFolio;
NSMutableString *soapResultsPortFolio;
NSURLConnection *conn;
//---xml parsing---
NSXMLParser *xmlParserPortFolio;
BOOL elementFoundPortFolio;
NSMutableURLRequest *req;
NSString *theXMLPortFolio;
NSString *strSoapMsg;
UIAlertView *alertView;
在.m文件中使用以下代码:
-(void)callURL
{
//Your logic to call URL.
conn = [[NSURLConnection alloc] initWithRequest:req delegate:self];
if (conn)
{
webPortFolio = [[NSMutableData data] retain];
}
}
要处理响应,您可以使用以下功能:
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[webPortFolio setLength:0];
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[webPortFolio appendData:data];
}
-(void) connection:(NSURLConnection *) connection didFailWithError:(NSError *) error
{
NSLog(@"error...................%@",[error description]);
[webPortFolio release];
[connection release];
}
-(void) connectionDidFinishLoading:(NSURLConnection *) connection
{
//Check the request and returns the response.
NSLog(@"DONE. Received Bytes: %d", [webPortFolio length]);
theXMLPortFolio = [[NSString alloc]
initWithBytes: [webPortFolio mutableBytes]
length:[webPortFolio length]
encoding:NSUTF8StringEncoding];
//---shows the XML---
NSLog(@"shows the XML %@",theXMLPortFolio);
[theXMLPortFolio release];
if(xmlParserPortFolio)
{
[xmlParserPortFolio release];
}
xmlParserPortFolio = [[NSXMLParser alloc] initWithData: webPortFolio];
[xmlParserPortFolio setDelegate: self];
[xmlParserPortFolio setShouldResolveExternalEntities:YES];
[xmlParserPortFolio parse];
[webPortFolio release];
[connection release];
}
//---when the start of an element is found---
-(void) parser:(NSXMLParser *) parser
didStartElement:(NSString *) elementName
namespaceURI:(NSString *) namespaceURI
qualifiedName:(NSString *) qName
attributes:(NSDictionary *) attributeDict
{
if( [elementName isEqualToString:@"GetPortfolioListResult"])
{
if (!soapResultsPortFolio)
{
soapResultsPortFolio = [[NSMutableString alloc] init];
}
elementFoundPortFolio = TRUE;
NSLog(@"Registration...%@",soapResultsPortFolio);
}
else if([elementName isEqualToString:@"your_tag_name"])
{
elementFoundPortFolio = TRUE;
}
else if([elementName isEqualToString:@"your_tag_name"])
{
elementFoundPortFolio = TRUE;
}
else if([elementName isEqualToString:@"your_tag_name"])
{
elementFoundPortFolio = TRUE;
}
}
-(void)parser:(NSXMLParser *) parser foundCharacters:(NSString *)string
{
if (elementFoundPortFolio)
{
[soapResultsPortFolio appendString: string];
}
}
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError
{
NSLog(@"Parser error %@ ",[parseError description]);
}
//---when the end of element is found---
-(void)parser:(NSXMLParser *)parser
didEndElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName
{
if ([elementName isEqualToString:@"GetPortfolioListResult"])
{
NSLog(@"display the soap results%@",soapResultsPortFolio);
}
else if([elementName isEqualToString:@"your_tag_name"])
{
//Perform required action
}
else if([elementName isEqualToString:@"your_tag_name"])
{
//Perform required action
}
else if([elementName isEqualToString:@"your_tag_name"])
{
//Perform required action
}
[soapResultsPortFolio setString:@""];
elementFoundPortFolio = FALSE;
}
编辑:
if ([elementName isEqualToString:@"media:thumbnail"])
{
//Save your URL in an Array
}