0

解析された Yahoo RSS フィードをテーブル ビューに表示しようとしています。しかし、画面には何も表示されません。ブレークポイントを使用すると、コントロールが cellForRowAtIndexPath メソッドにまったく移動しないことがわかりました。なぜそれが起こっているのかわかりません。yahoo フィードの構造は次のとおりです。

 <?xml version="1.0" encoding="utf-8"?>
    <rss xmlns:media="http://search.yahoo.com/mrss/" version="2.0">
    <channel>
    <title>Yahoo! News - Latest News &amp; Headlines</title>
    <link>http://news.yahoo.com/</link>
    <description>The latest news and headlines from Yahoo! News. Get breaking news stories and in-depth coverage with videos and photos.</description>
    <language>en-US</language>
    <copyright>Copyright (c) 2013 Yahoo! Inc. All rights reserved</copyright>
    <pubDate>Sun, 21 Apr 2013 17:08:00 -0400</pubDate>
    <ttl>5</ttl>
    <image>
    <title>Yahoo! News - Latest News &amp; Headlines</title>
    <link>http://news.yahoo.com/</link>
    <url>http://l.yimg.com/a/i/us/nws/th/main_142c.gif</url>
    </image>
    <item><title>After the bombings, the blame game begins</title><description>&lt;p&gt;&lt;a href="http://news.yahoo.com/boston-marathon-bombing-blame-game-begins-210800101.html"&gt;&lt;img src="http://l3.yimg.com/bt/api/res/1.2/uiv31afw5K_BzPxeYQz44Q--/YXBwaWQ9eW5ld3M7Zmk9ZmlsbDtoPTg2O3E9ODU7dz0xMzA-/http://media.zenfs.com/en_us/News/Reuters/2013-04-22T013026Z_741208741_GM1E94M0Q7101_RTRMADP_3_USA-EXPLOSIONS-BOSTON.JPG" width="130" height="86" alt="A couple embraces at a memorial on Boylston Street to the victims of the Boston Marathon bombings in Boston" align="left" title="A couple embraces at a memorial on Boylston Street to the victims of the Boston Marathon bombings in Boston" border="0" /&gt;&lt;/a&gt;Some lawmakers fault the FBI for not following up on intelligence about one of the alleged bombers.&lt;/p&gt;&lt;br clear="all"/&gt;</description><link>http://news.yahoo.com/boston-marathon-bombing-blame-game-begins-210800101.html</link><pubDate>Sun, 21 Apr 2013 17:08:00 -0400</pubDate><source url="http://www.csmonitor.com/">Christian Science Monitor</source><guid isPermaLink="false">boston-marathon-bombing-blame-game-begins-210800101</guid><media:content url="http://l3.yimg.com/bt/api/res/1.2/uiv31afw5K_BzPxeYQz44Q--/YXBwaWQ9eW5ld3M7Zmk9ZmlsbDtoPTg2O3E9ODU7dz0xMzA-/http://media.zenfs.com/en_us/News/Reuters/2013-04-22T013026Z_741208741_GM1E94M0Q7101_RTRMADP_3_USA-EXPLOSIONS-BOSTON.JPG" type="image/jpeg" width="130" height="86"></media:content><media:text type="html">&lt;p&gt;&lt;a href="http://news.yahoo.com/boston-marathon-bombing-blame-game-begins-210800101.html"&gt;&lt;img src="http://l3.yimg.com/bt/api/res/1.2/uiv31afw5K_BzPxeYQz44Q--/YXBwaWQ9eW5ld3M7Zmk9ZmlsbDtoPTg2O3E9ODU7dz0xMzA-/http://media.zenfs.com/en_us/News/Reuters/2013-04-22T013026Z_741208741_GM1E94M0Q7101_RTRMADP_3_USA-EXPLOSIONS-BOSTON.JPG" width="130" height="86" alt="A couple embraces at a memorial on Boylston Street to the victims of the Boston Marathon bombings in Boston" align="left" title="A couple embraces at a memorial on Boylston Street to the victims of the Boston Marathon bombings in Boston" border="0" /&gt;&lt;/a&gt;Some lawmakers fault the FBI for not following up on intelligence about one of the alleged bombers.&lt;/p&gt;&lt;br clear="all"/&gt;</media:text><media:credit role="publishing company"></media:credit></item></guid></channel>
</rss>

私の feedViewController.m は次のとおりです。

@interface feedViewController ()

    @end

    @implementation feedViewController

    @synthesize tableView,showPosts;
    //@synthesize feed;

    Feed *xmlParseFeed;
    //channel *chShow;

    - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
    {
        self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
        if (self) {
            // Custom initialization
        }
        return self;
    }


    - (void)viewDidLoad
    {
        [super viewDidLoad];
        //self.feed = [[Feed alloc] init];
        self.showPosts = [[NSMutableArray alloc] init];

        NSArray *newPosts = [xmlParseFeed newPosts];

        if (newPosts) {   
            [self.showPosts addObjectsFromArray:newPosts];
            //[newPosts release];
        }

        static NSString *feedURLString = @"http://news.yahoo.com/rss";
        NSURL *feedURL = [NSURL URLWithString:feedURLString];
        xmlParseFeed = [[Feed alloc] initWithURL:feedURL];
        self.showPosts = [[NSMutableArray alloc] init];

        [xmlParseFeed refresh];
    }

    - (void)viewDidUnload
    {
        [self setTableView:nil];
        [super viewDidUnload];
        // Release any retained subviews of the main view.
    }
    - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
    {
        return 1;
    }
    - (NSInteger)tableView:(UITableView *)tableView
     numberOfRowsInSection:(NSInteger)section {

        return [showPosts count];
    }
    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
        static NSString *CellIdentifier = @"Cell";

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

        ItemDataCollection *post = [showPosts objectAtIndex:indexPath.row];
         Feed *entry = [showPosts objectAtIndex:indexPath.row];
        // Set up the cell...
            channel *channelRecord = [self.showPosts objectAtIndex:indexPath.row];
        cell.textLabel.text = channelRecord.cTitle;
        cell.textLabel.text = channelRecord.pubDate;
        NSLog(@"channelRecord.title *****************%@",channelRecord.cTitle);    

      /*  cell.textLabel.text = post.title;
        cell.textLabel.text = post.itemDescription;
        cell.textLabel.text = post.titleImage;
        NSLog(@"item title******%@",post.title); */




        cell.textLabel.font=[UIFont fontWithName:@"Arial" size:12];
        cell.textLabel.numberOfLines = 1;





       return cell;
    }
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

@end

Properties in channel class are: cTitle,pubDate and itemCollectionArray. Properties in Post class are: title, itemDescription and titleImage. Feed class is for parsing. the contents of Feed.m is as follows:

 @class ItemDataCollection;
    @implementation Feed
    @synthesize feedURL,feedRequest,currentElement,currentElementData;
    //@synthesize feedChannel;
    //@synthesize feedPosts;
    static ItemDataCollection *itemCollection;
    static NSMutableArray *channelCollection;
    NSMutableString *mString;
    NSMutableString *str;
    channel *Channel ;
    - (NSArray *)newPosts {
        NSMutableArray *posts = [[NSMutableArray alloc] init];

        for (NSInteger item = 1; item <= 5; item++) {
            //NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
            ItemDataCollection *newPost;
            newPost = [[ItemDataCollection alloc] init];
          // NSString *pubDate = [NSDate dateWithTimeIntervalSinceNow:@"pubDate"];
       newPost.title = [NSString stringWithFormat:@"title %@", kTitleElementName];
            newPost.itemDescription = [NSString stringWithFormat:@"itemdescription %@", kItemDescription];
            newPost.titleImage = [NSString stringWithFormat:@"image %@",kItemImage];
         //   newPost.itemTitle = [NSString stringWithFormat:@"itemtitle %@", ITEM_TITLE_XML];

            [posts addObject:newPost];
            //[newPost release];

           // [pool drain];
        }
        return posts;
    }


    - (Feed *) initXMLParser {

        //[super init];

        appDelegate = (appAppDelegate *)[[UIApplication sharedApplication] delegate];

        return self;
    }
    -(id)initWithURL:(NSURL *)sourceURL {
        if (self = [super init]) {  
             self.feedURL = sourceURL;

            channelCollection=[[NSMutableArray alloc] init];
        }
        return self;
    }
    - (void)refresh {
        self.feedRequest = [ASIHTTPRequest requestWithURL:feedURL];

      //  [feedPosts removeAllObjects];
        [feedRequest setDelegate:self];
        [feedRequest startAsynchronous];
    }
    - (void)requestFinished:(ASIHTTPRequest *)request {
        NSData *responseData = [request responseData];
       // NSLog(@"*************response are *********%@",[[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding]);

        NSXMLParser *parser = [[NSXMLParser alloc] initWithData:responseData];
        [parser setDelegate:self];
        if ([parser parse]) {

            [[NSNotificationCenter defaultCenter] 
             postNotificationName:@"myevent"
             object:nil];
           // [posts ]

        }    
    }

    - (void)requestFailed:(ASIHTTPRequest *)request {
        NSError *error = [request error];
        NSLog(@"requestFailed: %@", [error localizedDescription]);
    } 

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

        if ([elementName isEqualToString:kChannelElementName]) {
            Channel = [[channel alloc] init];
            dict=[[NSMutableDictionary alloc] init];
            [Channel setItemCollectionArray:[[NSMutableArray alloc] init]];


            return ;
    }

        if ([elementName isEqualToString:kItemElementName]) {
           itemCollection=[[ItemDataCollection alloc] init];


            return ;
         }
        if ([elementName isEqualToString:kTitleElementName]) {


            return ;

        }
      if([elementName isEqualToString:kItemDescription]){
            return ;
        }
        if ([elementName isEqualToString:kItemImage]) {
            NSString *urlString = attributeDict[@"url"];
            if(urlString){
                [dict setObject:urlString forKey:@"img"];
                NSLog(@"%@",urlString);
                mString = [NSString stringWithFormat:urlString];
                str = [NSString stringWithFormat:mString];
            }

            return ;
        }

    }

    - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {

        if (currentElementData == nil) {
            self.currentElementData = [[NSMutableString alloc] init];
        }

        [currentElementData appendString:string];     
    }
    - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName
      namespaceURI:(NSString *)namespaceURI
     qualifiedName:(NSString *)qName {

        if ([elementName isEqualToString:kChannelElementName]) {
            [channelCollection addObject:Channel];

            NSLog(@"channel are***********%@",channelCollection);
            for(ItemDataCollection *mydata in Channel.itemCollectionArray){
                NSLog(@"___%@ <><><><><> desc \n   <><><><><><> img \n        %@",mydata.title,/*mydata.itemDescription*/mydata.titleImage);

            }

            Channel =nil;

        }

       else  if ([elementName isEqualToString:kItemElementName]) {
           [[Channel itemCollectionArray] addObject:itemCollection];
           itemCollection=nil;

            }
       else  if ([elementName isEqualToString:kTitleElementName]) {
           if(itemCollection==nil){

           Channel.cTitle=currentElementData;
           }
           else{

               itemCollection.title=currentElementData;

           }



       }
       else  if ([elementName isEqualToString:kPubDate]) {
           Channel.pubDate=currentElementData;


       }
      else  if ([elementName isEqualToString: kItemDescription]) {
          if(itemCollection!=nil){
           itemCollection.itemDescription = currentElementData;


       } 
      }
      else if([currentElementData rangeOfString:@"media:content"].location){

          if(itemCollection!=nil){

          if([str isEqualToString:mString]){
                //  [currentElementData appendString:dict];
                  itemCollection.titleImage = mString;
          } else{
              itemCollection.titleImage = @"";
          }
          }
      }



        self.currentElementData = nil;
    }
    - (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError {

        NSString *info = [NSString stringWithFormat:
                          @"Error %i, Description: %@, Line: %i, Column: %i",
                          [parseError code],
                          [[parser parserError] localizedDescription],
                          [parser lineNumber],
                          [parser columnNumber]];

        NSLog(@"RSS Feed Parse Error: %@", info);
    }

    @end

フィードが解析され、コンソールに表示されます。しかし、画面には表示されません。その理由は何ですか？先ほども言いましたが、cellForRowAtIndexPath() はまったくアクセスされていません。その理由は何ですか??

このメソッドを追加しました：

- (void)feedChanged:(NSNotification *)notification {
    NSArray *newPosts = [xmlParseFeed newPosts];

    NSLog(@"%@",newPosts);
    if (newPosts) {

        [self.showPosts addObjectsFromArray:newPosts];
        [self.tableView reloadData];
       // [self updateViewTitle];
       // [newPosts release];
   }
4

1 に答える 1

0

UITableView から reloadData を呼び出しているコードの場所がわかりません。newPosts を読み込んだ後、このメソッドを呼び出す必要があります。

これが機能しない場合は、次のようないくつかのことを確認してください。

  1. tableView:numberOfRowsInSection: によって返される値は何ですか? ゼロより大きいですか？ゼロの場合、それが tableView:cellForRowAtIndexPath が呼び出されない理由です。

  2. フィードをどのようにロードしますか? それはメインスレッドにありますか、それとも別のスレッドにありますか? 別のスレッドでロードする必要があるため、データのロード中に UI をブロックすることはありませんが、データが newPosts にロードされた後に reloadData を呼び出していることを確認してください。

于 2013-04-22T05:50:53.890 に答える