ActivityIndicator doesn't stop animating nor removes from superview in UICollectionViewCell - objective-c

Question

I am trying to implement UICollectionView and show images. I am using SDWebimage which works perfectly in tableviewcells but when i tried to use it in UICollectionviewCell it doesn't stop and remove activityindicator. It does place the placeholder image if there is no downloaded image. I am not sure what is the difference between tableviewcell and collectionviewcell that might cause this problem.
Here is the code:
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"personImageCell";
PersonCollectionViewCell *cell = (PersonCollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];
Person *person = [self.fetchedResultsController objectAtIndexPath:indexPath];
NSString *imgURL=[person.imageurl stringByAppendingString:#"?maxheight=300&maxwidth=400"];
UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
activityIndicator.hidesWhenStopped = YES;
activityIndicator.hidden = NO;
[activityIndicator startAnimating];
activityIndicator.center = CGPointMake(cell.ivPersonImage.frame.size.width /2, cell.ivPersonImage.frame.size.height/2);
[cell.ivPersonImage setImageWithURL:[NSURL URLWithString:imgURL] placeholderImage:nil options:SDWebImageProgressiveDownload success:^(UIImage *image, BOOL cached){
[activityIndicator stopAnimating];[activityIndicator removeFromSuperview];
NSLog(#"activity indicator should be removed");
}failure:^(NSError *error){
[activityIndicator stopAnimating];[activityIndicator removeFromSuperview];
cell.ivPersonImage.image = [UIImage imageNamed:#"placeholder.png"];
}];
[cell.ivPersonImage addSubview:activityIndicator];
return cell;
}
UPDATE:
When i do NSLog(#"activity indicator should be removed %#,activityIndicator);
I get this output:
activity indicator should be removed <UIActivityIndicatorView: 0xa520ab0; frame = (65 90; 20 20); hidden = YES; layer = <CALayer: 0xa520b60>>
It shows that UIActivityindicator is hidden but it is still showing on top of the image

Answer 1

It seems that you are reusing cell so there are more then one UIActivityIndicatorViews.
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"personImageCell";
PersonCollectionViewCell *cell = (PersonCollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];
Person *person = [self.fetchedResultsController objectAtIndexPath:indexPath];
NSString *imgURL=[person.imageurl stringByAppendingString:#"?maxheight=300&maxwidth=400"];
UIActivityIndicatorView *activityIndicator = [cell.ivPersonImage viewWithTag:10];
if (activityIndicator) [activityIndicator removeFromSuperview];
activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
activityIndicator.hidesWhenStopped = YES;
activityIndicator.hidden = NO;
[activityIndicator startAnimating];
activityIndicator.center = cell.ivPersonImage.center;
activityIndicator.tag = 10;
[cell.ivPersonImage addSubview:activityIndicator];
[cell.ivPersonImage setImageWithURL:[NSURL URLWithString:imgURL] placeholderImage:nil options:SDWebImageProgressiveDownload success:^(UIImage *image, BOOL cached){
[activityIndicator stopAnimating];[activityIndicator removeFromSuperview];
NSLog(#"activity indicator should be removed");
}failure:^(NSError *error){
[activityIndicator stopAnimating];[activityIndicator removeFromSuperview];
cell.ivPersonImage.image = [UIImage imageNamed:#"placeholder.png"];
}];
return cell;
}

Answer 2

Hmm....this is weird..can you try to make sure the activityIndicator is working on the main thread -
[cell.ivPersonImage setImageWithURL:[NSURL URLWithString:imgURL] placeholderImage:nil options:SDWebImageProgressiveDownload success:^(UIImage *image, BOOL cached){
dispatch_async(dispatch_get_main_queue(), ^(void){
[activityIndicator stopAnimating];
[activityIndicator removeFromSuperview];
}
NSLog(#"activity indicator should be removed");
}failure:^(NSError *error){
dispatch_async(dispatch_get_main_queue(), ^(void){
[activityIndicator stopAnimating];
[activityIndicator removeFromSuperview];
}
cell.ivPersonImage.image = [UIImage imageNamed:#"placeholder.png"];
}];
I suspect it is not, that is why it is not stopping its animation.

Answer 3

Create the activity indicator in the ViewDidLoad of current View Controller
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(150, 225, 20, 30)];
[spinner setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleGray];
spinner.color = [UIColor blueColor];
[self.view addSubview:spinner];
Use below code right in the beginning of the function which leads to the activity
[NSThread detachNewThreadSelector:#selector(threadStartAnimating:) toTarget:selfwithObject:nil];
Declare these two methods for starting and stoping the Animation
-(void)threadStartAnimating:(id)data
{
[spinner startAnimating];
}
-(void)threadStopAnimating:(id)data
{
[spinner stopAnimating];
}
Please give feedback as this code is working fine in my own project