iPhone XML解析問題

Question

我是iPhone開發新手，我試圖解析此鏈接並將其放在我的桌面視圖上，但是當我的桌面視圖顯示時，標題不顯示在行中。我在這裏做錯了什麼？

- (void)viewDidLoad { 
[super viewDidLoad]; 

self.title = @"RSS Feeds"; 

rssList = [[NSMutableArray alloc] initWithCapacity:1]; 

NSString *URLString = [[NSString alloc]initWithFormat:@"http://www.rpg.net/index.xml"]; 
NSLog(@"%@",URLString); 



NSURL *xmlURL = [NSURL URLWithString:URLString]; 


NSXMLParser *firstParser = [[NSXMLParser alloc] initWithContentsOfURL:xmlURL]; 
[firstParser setDelegate:self]; 
[firstParser parse]; 

[URLString release]; 
} 

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

if ([elementName compare:@"item"] == NSOrderedSame) { 

[rssList addObject:[[NSDictionary alloc] initWithObjectsAndKeys: 
[attributeDict objectForKey:@"title"],@"title", 
[attributeDict objectForKey:@"link"],@"link", 
nil]]; 

} 
} 

Answer 1

將此用於從rss提要進行xml解析。

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { 
return 1; 
} 


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { 
return [stories count]; 
} 


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { 

static NSString *MyIdentifier = @"MyIdentifier"; 

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier]; 
if (cell == nil) { 
    cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease]; 
} 

// Set up the cell 
int storyIndex = [indexPath indexAtPosition: [indexPath length] - 1]; 
[cell setText:[[stories objectAtIndex: storyIndex] objectForKey: @"title"]]; 

return cell; 
} 


- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { 
// Navigation logic 

int storyIndex = [indexPath indexAtPosition: [indexPath length] - 1]; 

NSString * storyLink = [[stories objectAtIndex: storyIndex] objectForKey: @"link"]; 

// clean up the link - get rid of spaces, returns, and tabs... 
storyLink = [storyLink stringByReplacingOccurrencesOfString:@" " withString:@""]; 
storyLink = [storyLink stringByReplacingOccurrencesOfString:@"\n" withString:@""]; 
storyLink = [storyLink stringByReplacingOccurrencesOfString:@" " withString:@""]; 

NSLog(@"link: %@", storyLink); 
// open in Safari 
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:storyLink]]; 
    } 


    - (void)viewWillAppear:(BOOL)animated { 
[super viewWillAppear:animated]; 
    } 

    - (void)viewDidAppear:(BOOL)animated { 
[super viewDidAppear:animated]; 

if ([stories count] == 0) { 
    NSString * path = @"http://feeds.feedburner.com/TheAppleBlog"; 
    [self parseXMLFileAtURL:path]; 
} 

cellSize = CGSizeMake([newsTable bounds].size.width, 60); 
    } 

    - (void)viewWillDisappear:(BOOL)animated { 
    } 

    - (void)viewDidDisappear:(BOOL)animated { 
    } 




    - (void)parserDidStartDocument:(NSXMLParser *)parser{  
NSLog(@"found file and started parsing"); 

    } 

    - (void)parseXMLFileAtURL:(NSString *)URL 
    { 
stories = [[NSMutableArray alloc] init]; 

    //you must then convert the path to a proper NSURL or it won't work 
    NSURL *xmlURL = [NSURL URLWithString:URL]; 

// here, for some reason you have to use NSClassFromString when trying to alloc NSXMLParser, otherwise you will get an object not found error 
// this may be necessary only for the toolchain 
rssParser = [[NSXMLParser alloc] initWithContentsOfURL:xmlURL]; 

// Set self as the delegate of the parser so that it will receive the parser delegate methods callbacks. 
[rssParser setDelegate:self]; 

// Depending on the XML document you're parsing, you may want to enable these features of NSXMLParser. 
[rssParser setShouldProcessNamespaces:NO]; 
[rssParser setShouldReportNamespacePrefixes:NO]; 
[rssParser setShouldResolveExternalEntities:NO]; 

[rssParser parse]; 

    } 

    - (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError { 
NSString * errorString = [NSString stringWithFormat:@"Unable to download story feed from web site (Error code %i)", [parseError code]]; 
NSLog(@"error parsing XML: %@", errorString); 

UIAlertView * errorAlert = [[UIAlertView alloc] initWithTitle:@"Error loading content" message:errorString delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
[errorAlert show]; 
    } 

    - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{   
//NSLog(@"found this element: %@", elementName); 
currentElement = [elementName copy]; 
if ([elementName isEqualToString:@"item"]) { 
    // clear out our story item caches... 
    item = [[NSMutableDictionary alloc] init]; 
    currentTitle = [[NSMutableString alloc] init]; 
    currentDate = [[NSMutableString alloc] init]; 
    currentSummary = [[NSMutableString alloc] init]; 
    currentLink = [[NSMutableString alloc] init]; 
} 

    } 

    - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{  
//NSLog(@"ended element: %@", elementName); 
if ([elementName isEqualToString:@"item"]) { 
    // save values to an item, then store that item into the array... 
    [item setObject:currentTitle forKey:@"title"]; 
    [item setObject:currentLink forKey:@"link"]; 
    [item setObject:currentSummary forKey:@"summary"]; 
    [item setObject:currentDate forKey:@"date"]; 

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

    } 

    - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{ 
//NSLog(@"found characters: %@", string); 
// save the characters for the current item... 
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]; 
} 

    } 

    - (void)parserDidEndDocument:(NSXMLParser *)parser { 

[activityIndicator stopAnimating]; 
[activityIndicator removeFromSuperview]; 

NSLog(@"all done!"); 
NSLog(@"stories array has %d items", [stories count]); 
[newsTable reloadData]; 
    } 





    - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { 
// Return YES for supported orientations 
return (interfaceOrientation == UIInterfaceOrientationPortrait); 
    } 


    - (void)didReceiveMemoryWarning { 
[super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview 
// Release anything that's not essential, such as cached data 
    } 


    - (void)dealloc { 

[currentElement release]; 
[rssParser release]; 
[stories release]; 
[item release]; 
[currentTitle release]; 
[currentDate release]; 
[currentSummary release]; 
[currentLink release]; 

[super dealloc]; 
    }