TableView不显示博客的所有行

Question

I have a number of blog apps. Recently, some of them started experiencing some issues. I use ASIHTTP Classes and GDataXML Classes to parse the xml of a wordpress feed, and put each item (article) into a mutable array. The tableview is then supposed to load all of the stories into a cell for each article. The issue I am having is that new articles are not being displayed on first run, the user is having to Pull to Refresh, and then the new article displays. I ran a test just now on an app. The article was posted a few hours ago. I ran the app, it wasn't there. Pulled to refresh, it showed. Closed down the app completely, restarted it, and it was gone again. Here is the code in the TableView's implementation:

@implementation RootViewController


- (void)refresh {
    self.allEntries = [NSMutableArray array];
    self.queue = [[[NSOperationQueue alloc] init] autorelease];
    self.feeds = [NSArray arrayWithObjects:@"http://bubblycandacebabbles.wordpress.com/?cat=-2008&feed=rss2",
                  nil];


    for (NSString *feed in _feeds) {
        NSURL *url = [NSURL URLWithString:feed];
        ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
        [request setDelegate:self];
        [_queue addOperation:request];
    }

}

- (void)viewDidLoad {
    [super viewDidLoad];    
    [activity startAnimating];
    //[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"navbarcopy.png"] forBarMetrics:UIBarMetricsDefault];
    self.title = @"Blog";
        CGFloat nRed=111.0/255.0;
    CGFloat nBlue=209/255.0;
    CGFloat nGreen=229.0/255.0;
    UIColor *myColor=[[UIColor alloc]initWithRed:nRed green:nBlue blue:nGreen alpha:1];
    UIBarButtonItem *font = [[UIBarButtonItem alloc] initWithTitle:@"Change Font Size" style:UIBarButtonItemStylePlain target:self action:@selector(fontsizes)];
    self.navigationController.navigationItem.rightBarButtonItem = font;
    self.tableView.backgroundColor = myColor;

    self.refreshControl = [[UIRefreshControl alloc] init];

    [self.refreshControl addTarget:self action:@selector(refreshInvoked:forState:) forControlEvents:UIControlEventValueChanged];
    [self refresh];
}
-(void) refreshInvoked:(id)sender forState:(UIControlState)state {
    // Refresh table here...
    [_allEntries removeAllObjects];
    [self.tableView reloadData];
    [self refresh];
}

- (void)parseRss:(GDataXMLElement *)rootElement entries:(NSMutableArray *)entries {

    NSArray *channels = [rootElement elementsForName:@"channel"];
    for (GDataXMLElement *channel in channels) {            

        NSString *blogTitle = [channel valueForChild:@"title"];                    

        NSArray *items = [channel elementsForName:@"item"];
        for (GDataXMLElement *item in items) {

            NSString *articleTitle = [item valueForChild:@"title"];
            NSString *articleUrl = [item valueForChild:@"link"];            
            NSString *articleDateString = [item valueForChild:@"pubDate"];        
            NSDate *articleDate = [NSDate dateFromInternetDateTimeString:articleDateString formatHint:DateFormatHintRFC822];
            NSString *articleImage = [item valueForChild:@"content:encoded"];
            NSScanner *theScanner;
            NSString *gt =nil;
            theScanner = [NSScanner scannerWithString:articleImage];


            NSString *comments = [articleUrl stringByAppendingString:@"#respond"];
            NSString *commentslink = [NSString stringWithFormat: @"<a href=\"%@\">Leave A Comment</a>",comments];
            // find start of tag
            [theScanner scanUpToString:@"alt=\"\" width=" intoString:NULL] ; 

            // find end of tag
            [theScanner scanUpToString:@"/>" intoString:&gt] ;
            // replace the found tag with a space
            //(you can filter multi-spaces out later if you wish)
            NSString *test = [articleImage stringByReplacingOccurrencesOfString:[ NSString stringWithFormat:@"%@", gt] withString:@"alt=\"\" width=\"150\" height=\"150\""];
            NSString *final = [test stringByReplacingOccurrencesOfString:@"float:none;height:30px" withString:@"float:none;height:1px"]; 
            NSDateFormatter * dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
            [dateFormatter setTimeStyle:NSDateFormatterShortStyle];
            [dateFormatter setDateStyle:NSDateFormatterShortStyle];
            NSString *dateofarticle = [dateFormatter stringFromDate:articleDate];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
            NSString *smalltitle = [defaults objectForKey:@"Title"];
            NSString *smallbody = [defaults objectForKey:@"Article"];
            NSString *bodyoftext = [[[[[[[[[[[@"<head><body bgcolor=\"#6fd1e5\" text=\"#CC0099\"><style type='text/css'>a > img {pointer-events: none;cursor: default;max-width: 310;}</style></head><b><font size=" stringByAppendingString: smalltitle ] stringByAppendingString:@"><div align=\"left\"><FONT FACE=\"noteworthy\">" ]stringByAppendingString:articleTitle] stringByAppendingString:@"</font></b><font size=" ] stringByAppendingString:smallbody ] stringByAppendingString:@"><div align=\"left\"><FONT FACE=\"noteworthy\">"] stringByAppendingString:dateofarticle] stringByAppendingString:@"</div></p><FONT FACE=\"noteworthy\">"] stringByAppendingString:final] stringByAppendingString:commentslink]stringByAppendingString:@"</FONT>"];








            RSSEntry *entry = [[[RSSEntry alloc] initWithBlogTitle:blogTitle
                                                      articleTitle:articleTitle
                                                        articleUrl:articleUrl
                                                       articleDate:articleDate
                                                      articleImage:bodyoftext] autorelease];
            [entries addObject:entry];
        }      
    }

}


- (void)parseFeed:(GDataXMLElement *)rootElement entries:(NSMutableArray *)entries {

    if ([rootElement.name compare:@"rss"] == NSOrderedSame) {
        [self parseRss:rootElement entries:entries];
    } else if ([rootElement.name compare:@"feed"] == NSOrderedSame) {                       
        [self parseAtom:rootElement entries:entries];
    } else {
        NSLog(@"Unsupported root element: %@", rootElement.name);
    }    
}


// Customize the number of sections in the table view.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}


// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [_allEntries count];
}


// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";  

    Cell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {  
        cell = [[Cell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
    }



    RSSEntry *entry = [_allEntries objectAtIndex:indexPath.row];
    NSString *substring = @"http://bubblycandacebabbles.files.wordpress.com";
    NSRange textRange = [entry.articleImage rangeOfString:substring];

   if(textRange.location != NSNotFound){
        NSString *thearticleImage = entry.articleImage;
        NSRegularExpression *expression = [NSRegularExpression regularExpressionWithPattern:@"src=\"([^\"]+)\"" options:NSRegularExpressionCaseInsensitive error:NULL];
        NSString *someString = thearticleImage;
        NSString *oneurl = [someString substringWithRange:[expression rangeOfFirstMatchInString:someString options:NSMatchingCompleted range:NSMakeRange(0, [someString length])]];
       NSString *finalstring = [oneurl stringByReplacingOccurrencesOfString:@"src=\"" withString:@""];
       NSString *thefinalstring = [finalstring stringByReplacingOccurrencesOfString:@"\"" withString:@""];
        NSDateFormatter * dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
        [dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
        [dateFormatter setTimeStyle:NSDateFormatterShortStyle];
        [dateFormatter setDateStyle:NSDateFormatterShortStyle];
       CGFloat nRed=204.0/255.0;
       CGFloat nBlue=0/255.0;
       CGFloat nGreen=153.0/255.0;
       UIColor *myColortext=[[UIColor alloc]initWithRed:nRed green:nBlue blue:nGreen alpha:1];
        NSString *articleDateString = [dateFormatter stringFromDate:entry.articleDate];
        UIFont *cellFont = [UIFont fontWithName:@"noteworthy" size:16];
        UIFont *cellFont2 = [UIFont fontWithName:@"noteworthy" size:12];    
        CALayer * l = [cell.imageView layer];
        [l setMasksToBounds:YES];
        [l setCornerRadius:11];
        [l setBorderWidth:2.0];
        [l setBorderColor:[[UIColor blackColor] CGColor]];
        cell.textLabel.text = entry.articleTitle;
       cell.textLabel.numberOfLines = 2;
       cell.detailTextLabel.adjustsFontSizeToFitWidth = YES;

        cell.detailTextLabel.text = [NSString stringWithFormat:@"%@ - Mother May I Blog", articleDateString];

        cell.textLabel.font = cellFont;
        cell.detailTextLabel.font = cellFont2;
       cell.textLabel.textColor = myColortext;
       cell.detailTextLabel.textColor = myColortext;
        [cell.imageView setImageWithURL:[NSURL URLWithString:thefinalstring] placeholderImage:[UIImage imageNamed:@"iphoneicon@2x.png"]];


    }
   else    {
        CALayer * l = [cell.imageView layer];
        [l setMasksToBounds:YES];
        [l setCornerRadius:11];
        [l setBorderWidth:2.0];
        [l setBorderColor:[[UIColor blackColor] CGColor]];
        NSDateFormatter * dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
        [dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
        [dateFormatter setTimeStyle:NSDateFormatterShortStyle];
        [dateFormatter setDateStyle:NSDateFormatterShortStyle];
        NSString *articleDateString = [dateFormatter stringFromDate:entry.articleDate];
        UIFont *cellFont = [UIFont fontWithName:@"noteworthy" size:16];    
        UIFont *cellFont2 = [UIFont fontWithName:@"noteworthy" size:12];    
        cell.imageView.image = [UIImage imageNamed:@"iphoneicon@2x.png"];
        cell.textLabel.text = entry.articleTitle;
       cell.textLabel.numberOfLines = 2;
       cell.detailTextLabel.adjustsFontSizeToFitWidth = YES;

        cell.detailTextLabel.text = [NSString stringWithFormat:@"%@ - Mother May I Blog", articleDateString];
       CGFloat nRed=204.0/255.0;
       CGFloat nBlue=0/255.0;
       CGFloat nGreen=153.0/255.0;
       UIColor *myColortext=[[UIColor alloc]initWithRed:nRed green:nBlue blue:nGreen alpha:1];
        cell.textLabel.font = cellFont;
        cell.detailTextLabel.font = cellFont2;
       cell.textLabel.textColor = myColortext;
       cell.detailTextLabel.textColor = myColortext;


    }


    return cell;
}

Answer 1

You need to invoke

[self.tableView reloadData];

at some point after your data has finished loading. How exactly you do this is a bit tricky, you need some way of telling when your operation queue is empty. Alternatively, you could theoretically call it after each operation in the queue is complete, that way the table will populate one at a time. This could cause problems if the user is on a slow connection, as reloading the table can cause jumps in the user experience, and I'm not positive on the thread safety of calling reloadData from a different thread