Issue with overlapping images in UITableView cells - objective-c

Question

I have 2 tables in coredata sqlite Painter and Picture. With relationship one-to-many.
In table "picture" I have string attribute pictureName. I store pictures(153) on a disk
This code I add imageViews to cells:
- (void)viewDidLoad
{
[super viewDidLoad];
NSError *error = nil;
if (![[self fetchedResultsController] performFetch:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
self.tableView.transform = CGAffineTransformMakeRotation( -M_PI/2 );
self.tableView.showsHorizontalScrollIndicator = NO;
self.tableView.showsVerticalScrollIndicator = NO;
[self.tableView setFrame:CGRectMake(0, 156, 1024, 449)];
}
- (void)viewDidUnload
{
[self setTableView:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return YES;
}
#pragma mark - UITableView Delegate Methods
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[fetchedResultsController fetchedObjects] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
Painter *painter = [[fetchedResultsController fetchedObjects] objectAtIndex:section];
//NSLog(#"%i", [painter.pictures count]);
return [painter.pictures count];
//return 152;
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
Painter *painter = [[fetchedResultsController fetchedObjects] objectAtIndex:indexPath.section];
Picture *picture = [[painter.pictures allObjects] objectAtIndex:indexPath.row];
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[NSString stringWithFormat:#"%#s.jpg", picture.imgName]]];
NSLog(#"add image %#s.jpg to sector:%i row:%i", picture.imgName, indexPath.section, indexPath.row);
imageView.transform = CGAffineTransformMakeRotation( M_PI/2 );
[cell addSubview:imageView];
[imageView release];
}
- (UITableViewCell *)tableView:(UITableView *)tableViewCurrent cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableViewCurrent dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell.
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
- (CGFloat)tableView:(UITableView *)aTableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return 300.0;
}
- (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (fetchedResultsController != nil) {
return fetchedResultsController;
}
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Painter" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:#"Main"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
return fetchedResultsController;
}
`
And I have problem: a lot of photo in every cell
http://ge.tt/9QX5lc4?c
(select view button)
Why?

Answer 1

Cells are being reused. Every time you are configuring a cell, you are adding an image view as a subview. Over time these accumulate and are providing the effect you are seeing. You should check if an image view already exists and assign an image to it or clean up the cell first and then set it up with an image.

Answer 2

The following code is what is causing the problem for you:
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableViewCurrent dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell.
[self configureCell:cell atIndexPath:indexPath];
return cell;
You're basically caching the cell the first time it's created and re-using it on subsequent calls to tableView:cellForRowAtIndexPath: If you don't want this to be cached then you'll need to create a new cell every time.
UITableViewCell *cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
// Configure the cell.
[self configureCell:cell atIndexPath:indexPath];
return cell;
This should fix your issue. There are more elaborate ways of handling cells such as caching it and manipulating its subviews directly instead of recreating it every time. Something to keep in mind as you continue to work on your code.