ios - 解析 RSS 提要时发送到实例的无法识别的选择器

Question

有问题的 Feed 是 https://fritchcoc.podbean.com/feed/

我的代码中有这个要解析，但每次运行它时，我都会收到以下错误消息。我试图添加异常断点，但它没有向我显示导致所有骚动的代码行。我已经花了两个小时来解决这个问题，但一点运气也没有。我在命令中将每个 NSString 都设置为 nil，以防万一 valueForChild 项中的一个出现错误，但即使全部为 nil，它们也有问题。

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[RSSEntry initWithBlogTitle:articleTitle:articleUrl:articleDate:articleImage:contentEncoded:]: unrecognized selector sent to instance

- (void)viewDidLoad {
    [super viewDidLoad];

    self.allEntries = [NSMutableArray array];
    self.queue = [[[NSOperationQueue alloc] init] autorelease];
    self.feeds = [NSArray arrayWithObjects:@"https://fritchcoc.podbean.com/feed/",
                  nil];   


    [self refresh];
}

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

}

- (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);
    }    
}

- (void)requestFinished:(ASIHTTPRequest *)request {
    [_queue addOperationWithBlock:^{
        NSError *error;
        GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithData:[request responseData] 
                                                               options:0 error:&error];
        if (doc == nil) { 
            NSLog(@"Failed to parse %@", request.url);
        } else {
            NSMutableArray *entries = [NSMutableArray array];
            [self parseFeed:doc.rootElement entries:entries];                

            [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                //int newCounter = 0;

                for (RSSEntry *entry in entries) {
                  //  newCounter++;
                    int insertIdx = [_allEntries indexForInsertingObject:entry sortedUsingBlock:^(id a, id b) {
                        RSSEntry *entry1 = (RSSEntry *) a;
                        RSSEntry *entry2 = (RSSEntry *) b;
                        return [entry1.articleDate compare:entry2.articleDate];
                    }];

                    [_allEntries insertObject:entry atIndex:insertIdx];
                    [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:[NSIndexPath indexPathForRow:insertIdx inSection:0]]
                                          withRowAnimation:nil];
                   /* if (newCounter > 999) {
                        break;
                    }*/
                }                            
            }];
        }        
    }];
}

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

- (void)parseRss:(GDataXMLElement *)rootElement entries:(NSMutableArray *)entries {
    NSLog(@"Go");
    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 *articleDateString = [item valueForChild:@"pubDate"];
            NSString *theCategory = [item valueForChild:@"category"];
            NSDate *articleDate = [NSDate dateFromInternetDateTimeString:articleDateString formatHint:DateFormatHintRFC822];
            NSString *articleUrl = [[[[item elementsForName: @"enclosure"] lastObject] attributeForName: @"url"] stringValue];
            NSString *picture = [[[[item elementsForName: @"media:content"] lastObject] attributeForName: @"href"] stringValue];
            RSSEntry *entry = [[[RSSEntry alloc] initWithBlogTitle:blogTitle 
                                                      articleTitle:articleTitle 
                                                        articleUrl:articleUrl 
                                                       articleDate:articleDate
                                                        articleImage:picture
                                                        contentEncoded:nil
                                                        category:theCategory] autorelease];
            if ([theCategory isEqualToString:@"Sermon"]) {
                [entries addObject:entry];
            }
        }
    }
}

Answer 1

在你的代码中你有这样的调用:

    RSSEntry *entry = [[[RSSEntry alloc] initWithBlogTitle:blogTitle 
                                              articleTitle:articleTitle 
                                                articleUrl:articleUrl 
                                               articleDate:articleDate
                                                articleImage:picture
                                                contentEncoded:nil
                                                category:theCategory] autorelease];

它有一个“类别”最后一个参数，但您的错误消息没有:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[RSSEntry initWithBlogTitle:articleTitle:articleUrl:articleDate:articleImage:contentEncoded:]: unrecognized selector sent to instance

是否有可能您制作了一个具有“类别”的新版本 RSSEntry，但没有正确地重新编译您的一些解析代码，并且该代码仍在尝试调用旧方法(没有“类别”) ？如果是这样，就做一个产品-“清理”-“构建”，并注意编译错误和警告。

我注意到您仍然没有使用 ARC(称为“autorelease”)，这向我表明这是一个非常古老的代码:)