Question

我正在尝试在我的应用中使用MWFeedParser库。在我的主屏幕上，我有一个名为NewsViewController的视图控制器。在MWFeedParser库中，根视图控制器称为RootViewController。我试图将RootViewController中的所有代码复制到NewsViewController .H + .M中，并且在IB中我将tableview链接到“dataSource”和“delegate”。但是当我的应用程序启动时，tableview是空的。以下是代码的编写方式：

·H：

 #import <UIKit/UIKit.h>
    #import "MWFeedItem.h"
    #import "MWFeedParser.h"

    @interface NewsViewController : UITableViewController  <MWFeedParserDelegate, UITableViewDelegate, UITableViewDataSource> {

        // Parsing
        MWFeedParser *feedParser;
        NSMutableArray *parsedItems;

        // Displaying
        NSArray *itemsToDisplay;
        NSDateFormatter *formatter;
        IBOutlet UITableView *tableView;
    }

    // Properties
    @property (nonatomic, retain) NSArray *itemsToDisplay;
    @property (nonatomic, retain) IBOutlet UITableView *tableView;
    -(IBAction)goHome;

    @end

.M：

#import "NSString+HTML.h"
#import "MWFeedParser.h"
#import "DetailTableViewController.h"

@implementation NewsViewController

@synthesize itemsToDisplay, tableView;


#pragma mark -
#pragma mark View lifecycle

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = NSLocalizedString(@"News", @"News");
        self.tabBarItem.image = [UIImage imageNamed:@"icon_news"];    }
    return self;
}

- (void)viewDidLoad
{
    label.shadowOffset = CGSizeMake(0.0f, 1.0f);
    label.textColor = [UIColor colorWithRed:0xB3/249.0 green:0xB3/252.0 blue:0xB3/253.0 alpha:1];
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    // Date
    // Setup
    formatter = [[NSDateFormatter alloc] init];
    [formatter setDateStyle:NSDateFormatterShortStyle];
    [formatter setTimeStyle:NSDateFormatterShortStyle];
    parsedItems = [[NSMutableArray alloc] init];
    self.itemsToDisplay = [NSArray array];

    // Refresh button
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh
                                                                                            target:self
                                                                                            action:@selector(refresh)];
    // Parse
    NSURL *feedURL = [NSURL URLWithString:@"http://www.mywebsite.com/feed/"];
    feedParser = [[MWFeedParser alloc] initWithFeedURL:feedURL];
    feedParser.delegate = self;
    feedParser.feedParseType = ParseTypeFull; // Parse feed info and all items
    feedParser.connectionType = ConnectionTypeAsynchronously;
    [feedParser parse];

    UIImage *someImage = [UIImage imageNamed:@"back_active1@2x.png"];
    [button setBackgroundImage:someImage forState:UIControlStateHighlighted];

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)viewDidAppear:(BOOL)animated {
    static BOOL first = YES;
    if (first) {
        UIViewController *popup = [[Home1ViewController alloc] initWithNibName:@"Home1ViewController" bundle:nil];

        [self presentViewController:popup animated:NO completion:nil];
        first = NO;
    }
}

#pragma mark -
#pragma mark Parsing

// Reset and reparse
- (void)refresh {
    self.title = @"Refreshing...";
    [parsedItems removeAllObjects];
    [feedParser stopParsing];
    [feedParser parse];
    self.tableView.userInteractionEnabled = NO;
    self.tableView.alpha = 0.3;
}

- (void)updateTableWithParsedItems {
    self.itemsToDisplay = [parsedItems sortedArrayUsingDescriptors:
                           [NSArray arrayWithObject:[[NSSortDescriptor alloc] initWithKey:@"date"
                                                                                 ascending:NO]]];
    self.tableView.userInteractionEnabled = YES;
    self.tableView.alpha = 1;
    [self.tableView reloadData];
}

#pragma mark -
#pragma mark MWFeedParserDelegate

- (void)feedParserDidStart:(MWFeedParser *)parser {
    NSLog(@"Started Parsing: %@", parser.url);
}

- (void)feedParser:(MWFeedParser *)parser didParseFeedInfo:(MWFeedInfo *)info {
    NSLog(@"Parsed Feed Info: “%@”", info.title);
    self.title = info.title;
}

- (void)feedParser:(MWFeedParser *)parser didParseFeedItem:(MWFeedItem *)item {
    NSLog(@"Parsed Feed Item: “%@”", item.title);
    if (item) [parsedItems addObject:item];
}

- (void)feedParserDidFinish:(MWFeedParser *)parser {
    NSLog(@"Finished Parsing%@", (parser.stopped ? @" (Stopped)" : @""));
    [self updateTableWithParsedItems];
}

- (void)feedParser:(MWFeedParser *)parser didFailWithError:(NSError *)error {
    NSLog(@"Finished Parsing With Error: %@", error);
    if (parsedItems.count == 0) {
        self.title = @"Failed"; // Show failed message in title
    } else {
        // Failed but some items parsed, so show and inform of error
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Parsing Incomplete"
                                                         message:@"There was an error during the parsing of this feed. Not all of the feed items could parsed."
                                                        delegate:nil
                                               cancelButtonTitle:@"Dismiss"
                                               otherButtonTitles:nil];
        [alert show];
    }
    [self updateTableWithParsedItems];
}

#pragma mark -
#pragma mark Table view data source

// 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 itemsToDisplay.count;
}

// Customize the appearance of table view cells.
- (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.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    }

    // Configure the cell.
    MWFeedItem *item = [itemsToDisplay objectAtIndex:indexPath.row];
    if (item) {

        // Process
        NSString *itemTitle = item.title ? [item.title stringByConvertingHTMLToPlainText] : @"[No Title]";
        NSString *itemSummary = item.summary ? [item.summary stringByConvertingHTMLToPlainText] : @"[No Summary]";

        // Set
        cell.textLabel.font = [UIFont boldSystemFontOfSize:15];
        cell.textLabel.text = itemTitle;
        NSMutableString *subtitle = [NSMutableString string];
        if (item.date) [subtitle appendFormat:@"%@: ", [formatter stringFromDate:item.date]];
        [subtitle appendString:itemSummary];
        cell.detailTextLabel.text = subtitle;

    }
    return cell;
}

#pragma mark -
#pragma mark Table view delegate

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

    // Show detail
    DetailTableViewController *detail = [[DetailTableViewController alloc] initWithStyle:UITableViewStyleGrouped];
    detail.item = (MWFeedItem *)[itemsToDisplay objectAtIndex:indexPath.row];
    [self.navigationController pushViewController:detail animated:YES];

    // Deselect
    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];

}

@end

请帮我解决这个问题！

Answer 1

您可以按照以下链接使用MWFeedParser：https://0club1.blogspot.in/

如果您的表视图为空，则可能出现以下错误：

NSURLSession / NSURLConnection HTTP加载失败

要允许HTTP，我们需要在App Transport Security设置中允许任意加载。在项目中选择info.plist，在信息属性列表中添加新列表作为App Transport Security Settings。在其中添加允许仲裁负载并将其标记为是。

如何在我的项目中实施MWFeedParser

1 个答案: