Question

I am creating a custom UITableViewCell to include an UIImageView and some related text. I am getting the images from the Internet and while the images load, I display a temporary UIImage.

I am using a separate thread to get the UIImage. Once an UIImage is downloaded, I am firing a method on the main thread to set the image in the UIImageView (getting the instance of UIImageView using tags)

But whatever I do, the images are not changed. The cells still display older images (corresponding to different row – due to reusing of cells) and new images are not reflected. Log statements show that the method to set the image is being called.

I even tried changing the image to a static image in willDisplayCell:forRowAtIndexPath: but even then the image does not change.

Edit
I tried calling reloadData on the UITableView after changing the UIImage, but the UIImage still does not change.

Here’s the relevant piece of code

cellForRowAtIndexPath

        image = [imagesArray valueForKey:[NSString stringWithFormat:@'%i',indexPath.row]];         if(image == nil){             //display temporary images. When scrolling stops, detach new thread to get images for rows visible             NSString *pth = [[NSBundle mainBundle] pathForResource:@'folder' ofType:@'png'];             image = [UIImage imageWithContentsOfFile:pth];             [imgView setImage:image];         }         else{             [imgView setImage:image];         } 

Method which is called on the main thread after an image is downloaded

-(void)setImageInArray:(NSIndexPath *)indPath{     [filesTable reloadData]; } 

In the thread, I am adding the UIImage object to imagesArray. So when the next time the cellForRowAtIndex method is called on reloadData, the new UIImage should be displayed.

Answer 1

UITableView’s cells are cached, so modifying the cell after it has been rendered will have no effect. Try sending the table a reloadData message, after updating the UIImageView.