从未在NSNotificationCenter中调用的selector方法

Question

我正在尝试使用NSNotificationCenter，由于某种原因，永远不会调用选择器方法。

- (NewsItem *) loadNewsItemDetail:(NewsItem *)currentNewsItem
{
    self.newsItem = currentNewsItem;

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(DownloadNewsItem) name:@"connectionDidFinishLoadingComplete" object:nil];

    return self.newsItem;
}

- (void) DownloadNewsItem:(NSNotification *) notification
{
    NSString *urlString = [Configuration newsStreamAPIURL:plNewsAPIKey];
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];

    (void)[[NSURLConnection alloc] initWithRequest:request delegate:self];
}


- (void)connectionDidFinishLoading:(NSURLConnection *)connection 
{       
    ...

    [[NSNotificationCenter defaultCenter] postNotificationName:@"connectionDidFinishLoadingComplete" object:nil];

}

根据我提供的内容永远不会调用我的DownloadNewsItem的原因是什么？

谢谢！

Answer 1

你的选择器方法需要冒号，因为它需要一个参数（在这种情况下为NSNotification）。

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(DownloadNewsItem:) name:@"connectionDidFinishLoadingComplete" object:nil];

Answer 2

您在:

之后忘记了DownloadNewsItem符号

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(DownloadNewsItem:)
                                             name:@"connectionDidFinishLoadingComplete"
                                           object:nil];