[Original] Open Source China Reading Note

First, let's take a look at the TableView method for getting the cell instance.

-(UITableViewCell *) tableView :( UITableView *) tableView cellForRowAtIndexPath :( NSIndexPath *) indexPath

Code involving Cell instantiation:

PostCell *cell = (PostCell * (!                NSArray *objects = [[NSBundle mainBundle] loadNibNamed: (NSObject *o ([o isKindOfClass:[PostCell = (PostCell **singleTap =            cell.img.image = [UIImage imageNamed:*p = ([cell.img.gestureRecognizers count] > *tap = (UITap *)[cell.img.gestureRecognizers objectAtIndex:                    tap.tag == self.catalog <=  ?  : == [UIFont boldSystemFontOfSize:= [NSString stringWithFormat:= [NSString stringWithFormat:                cell.img.image =  ([p.img isEqualToString:= [UIImage imageNamed:                    NSData * imageData ===                        IconDownloader *downloader = [imageDownloadsInProgress objectForKey:[NSString stringWithFormat: (downloader ==                            ImgRecord *record = [ImgRecord = cell;

Next, the implementation in startIconDownload: forIndexPath: Is to do the following:

1. instantiate IconDownloader and set it to imageDownloadsInProgress

2. iconDownloader instances use

NSURLConnection *conn =:self];

Asynchronous request

3. When the conn execution is complete, execute its delegate-IconDownloader finish method and cache the image

4. In the finish method, call delegate-PostView to render ImageData to image (png) data through UIImagePNGRepresentation, and call [tablePosts reloadData]

 

Here, it is worth noting: Is the reloadData method called once after each image is loaded optimal?