Terminated due to Memory Pressure By using AssetsLibrary.framework - alassetslibrary

Question

I am using AssetsLibrary.framework for fetching images from device gallery.I successfully fetched all images from gallery and displayed on my table view.Problem comes when I scroll up and down many times , I receive a memory issue warning getting printed on console and after some time it gets crashed saying CRASHED DUE TO MEMORY PRESSURE.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[TableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
ALAsset *asset = [self.images objectAtIndex:indexPath.row];
ALAssetRepresentation *representation = [asset defaultRepresentation];
image=[UIImage imageWithCGImage:[representation fullResolutionImage]];
[selectedAllImages addObject:image];
url = [representation url];
NSURL *imageURL=url;
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
{
ALAssetRepresentation *representation = [myasset defaultRepresentation];
fileName = [representation filename];
cell.cellLabel.text=fileName;
};
assetslibrary = [[ALAssetsLibrary alloc] init];
[assetslibrary assetForURL:imageURL
resultBlock:resultblock
failureBlock:nil];
[cell.cellImageView setImage:[UIImage imageWithCGImage:[asset thumbnail]]];
return cell;
}
So I need help where the mistake is?Thanks

Answer 1

ALAssetRepresentation *representation = [asset defaultRepresentation];
image=[UIImage imageWithCGImage:[representation fullResolutionImage]];
[selectedAllImages addObject:image];
url = [representation url];
Why do you getting fullResolutionImage in cellForRowAtIndexPath method? And putting into selectedAllImages array.. it seems like selectedAllImages array fills by fullresolutionimages infinity (during scrolling).
assetslibrary = [[ALAssetsLibrary alloc] init];
[assetslibrary assetForURL:imageURL
resultBlock:resultblock
failureBlock:nil];
Why you create assetslibrary and request for same asset (which have same url)?
I think you should simplify your 'cellForRowAtIndexPath' method, to be more lightweight during scrolling. Something like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[TableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
ALAsset *asset = [self.images objectAtIndex:indexPath.row];
ALAssetRepresentation *representation = [asset defaultRepresentation];
cell.cellLabel.text = [representation filename];
cell.cellImageView.image = [UIImage imageWithCGImage:[asset thumbnail]];
return cell;
}

Answer 2

The images you're loading from the asset library are going to be large. If your trying to load many of them on a table view then you will quickly run out of memory. The usual practice is to create scaled images from the larger images, which use a lot less memory.