花费太多时间从 RSS 提要加载新闻

Posted 2023-03-11

【中文标题】花费太多时间从 RSS 提要加载新闻

【英文标题】：Taking too much time in loading news from rss feed

【发布时间】：2013-05-13 11:19:14

【问题描述】：

我正在使用新闻应用程序。我有六个不同的消息。我从 viewwillappear() 方法调用 rss 提要。我已经使用 selectedIndex 运行了一个开关盒。我包括了延迟加载，但从 rss 加载新闻仍然需要很长时间。 任何可能的解决方案？ 提前致谢

(void)viewWillAppear:(BOOL)animated

    [super viewWillAppear:YES];

    noNewsLabel.hidden=YES;
    bdNewsParser=[[[BDNewsParser alloc] init]retain];
    if (loadingFlag==1)
    
        ImgesName=[[NSMutableArray alloc] init];
        dicImages_msg = [[NSMutableDictionary alloc] init];

    
    if (loadingFlag!=2)
    
        NSLog(@"newsTypeInd:%@",newsTypeInd);
        [newsCat setText:[newsTypeInd objectAtIndex:selectedIndex]];

        [newsTitleArray removeAllObjects];
        [newsDescriptionArray removeAllObjects];
        [newsLinkArray removeAllObjects];
        [newsPublicationDate removeAllObjects];
        [newsImageLinkArray removeAllObjects];
        [newsSourceArray removeAllObjects];

        switch(selectedIndex)
        
            case 0:
                 [bdNewsParser loadXMLByURL:@"http://amarhost.info/fuad/newsainment/itnews.php"];
                break;
            case 1: 
                [bdNewsParser loadXMLByURL:@"http://amarhost.info/fuad/newsainment/internationalnews.php"];
                break;
            case 2: 
              //   [bdNewsParser loadXMLByURL:@"http://amarhost.info/fuad/newsainment/bangladeshnews.php"];
                [self showAlert];

                break;
            case 3: 
                //[bdNewsParser loadXMLByURL:@"http://amarhost.info/fuad/newsainment/businessnews.php"];
                [self showAlert];

                break;
            case 4: 
                [bdNewsParser loadXMLByURL:@"http://amarhost.info/fuad/newsainment/entertainmentnews.php"];
                break;
            case 5: 
                  [bdNewsParser loadXMLByURL:@"http://amarhost.info/fuad/newsainment/sportnews.php"];
                break;
           default:
                break;
        


        newsTitleArray=bdNewsParser.titleArray;
        newsDescriptionArray=bdNewsParser.descriptionArray;
        newsLinkArray=bdNewsParser.linkArray;
        newsPublicationDate=bdNewsParser.publicationDateArray;
        newsImageLinkArray=bdNewsParser.newsImageArray;
        newsSourceArray=bdNewsParser.newsSourceArray;
        [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

        // [self filterArrayGroupWise:selectedIndex];


        if ([newsTitleArray count]==0) 
            NSLog(@"Hide contrrol");
            [self hideControls];
            noNewsLabel.hidden=NO;
        
        else 
            [self showControls];
            noNewsLabel.hidden=YES;
            [self setupScrollview];

            ImgesName = newsImageLinkArray;
            [self reloadScrolview];
        

        savedTitleArr=[userDefault readArrayFromUserDefaults:@"FavoriteTitle"];
        if (savedTitleArr)
        
            if ([savedTitleArr containsObject:[newsTitleArray objectAtIndex:pageNo]])
            
                [saveButton setEnabled:NO];
            
            else
            
                [saveButton setEnabled:YES];
            
        
        else
        
            [saveButton setEnabled:YES];
        
    

    indicatorAnimatingFlag=0;
    [activityView stopAnimating];

    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTapGestureCaptured:)];
    [scrollView addGestureRecognizer:singleTap];

    pageNo=0;
    CGRect frame = scrollView.frame;
    frame.origin.x = frame.size.width * 0;
    frame.origin.y = 0;
    [scrollView setBounds:frame];
    [bdNewsParser release];
    index=0;
    selectedIndex=0;
    

【参考方案1】：

您说“延迟加载”，但在哪里？在我看来，您拨打电话然后尝试访问其值：

case 0:
      [bdNewsParser loadXMLByURL:@"http://amarhost.info/fuad/newsainment/itnews.php"];
      break;

然后：

 newsTitleArray=bdNewsParser.titleArray;
        newsDescriptionArray=bdNewsParser.descriptionArray;
        newsLinkArray=bdNewsParser.linkArray;
        newsPublicationDate=bdNewsParser.publicationDateArray;
        newsImageLinkArray=bdNewsParser.newsImageArray;
        newsSourceArray=bdNewsParser.newsSourceArray;

【讨论】：

我没有给你具体的答案。只是指出你不是“延迟加载”任何东西。正确的术语是执行“异步任务”。 “懒加载”就是在你真正需要的时候做一些事情。

我采用了一个活动指示器，该指示器会在新闻和图像加载后进行动画处理，然后活动指示器就会停止。 [activityView startAnimating]; [activityView stopAnimating];

** 最后我使用执行选择器解决了它 ** - (void)viewWillAppear:(BOOL)animated indexNo=selectedIndex; newsCat.text=[newsTypeInd objectAtIndex:indexNo]; self.initialActivityIndicatorView.hidden=NO; [self.initialActivityIndicatorView startAnimating]; dateLabel.text=nil; [super viewWillAppear:YES]; [self performSelector:@selector(viewWillAppearForFlag0) withObject:nil afterDelay:0.5];