我对 Xcode 真的很陌生，但是在这里我遵循了本教程，甚至下载了该项目并尝试将其实现到我的中，但由于某种原因，我无法让它工作。我没有错误或任何东西。另外，我的表已经连接，所以我不知道问题是什么。这是我的一些代码：
视图控制器.h
@interface ThirdViewController : UIViewController <NSXMLParserDelegate>
{
IBOutlet UITableView * newsTable;
UIActivityIndicatorView * activityIndicator;
CGSize cellSize;
NSXMLParser * rssParser;
NSMutableArray * stories;
// a temporary item; added to the "stories" array one at a time, and cleared for the next one
NSMutableDictionary * item;
// it parses through the document, from top to bottom...
// we collect and cache each sub-element value, and then save each item to our array.
// we use these to track each current item, until it's ready to be added to the "stories" array
NSString * currentElement;
NSMutableString * currentTitle, * currentDate, * currentSummary, * currentLink;
}
- (void)parseXMLFileAtURL:(NSString *)URL;
@end
视图控制器.m
@implementation ThirdViewController
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (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] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier];
}
// Set up the cell
int storyIndex = [indexPath indexAtPosition: [indexPath length] - 1];
cell.textLabel.text=[[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"];
NSLog(@"%@",stories );
// clean up the link - get rid of spaces, returns, and tabs...
storyLink = [storyLink stringByReplacingOccurrencesOfString:@" " withString:@""];
storyLink = [storyLink stringByReplacingOccurrencesOfString:@"\n" withString:@""];
storyLink = [storyLink stringByReplacingOccurrencesOfString:@" " withString:@""];
// 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)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];
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
@end
我究竟做错了什么？