ALAssetsLibrary accessing all photos 1000 + from camera roll app crashes - objective-c

Question

I want to access all photos from camera roll my code is working fine if i have few images in camera roll then app is working fine but if i have more than 1000 photos then app crashes here is my code
ALAssetsLibrary *al = [[ALAssetsLibrary alloc] init];
[al enumerateGroupsWithTypes:ALAssetsGroupAll
usingBlock:^(ALAssetsGroup *group, BOOL *stop)
{
NSMutableArray *arrImages=[[NSMutableArray alloc]init];
NSString *albumName = [group valueForProperty:ALAssetsGroupPropertyName];
if (albumName !=nil) {
[arrGroupsNames addObject:albumName];
[group enumerateAssetsUsingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop)
{
if (asset)
{
UIImage *img=[self imageForAsset:asset];
[arrImages addObject:img];
}
}
];
[arrGroups addObject:arrImages];
}
[self.tableVieww reloadData];
}
failureBlock:^(NSError *error)
{
// User did not allow access to library
NSLog(#"error");
}
];
and here is the function which return image from ALAsset
-(UIImage*) imageForAsset:(ALAsset*) aAsset{
ALAssetRepresentation *rep;
rep = [aAsset defaultRepresentation];
return [UIImage imageWithCGImage:[rep fullResolutionImage]];
}

Answer 1

The issue is that be creating a UIImage for each photo in the users camera roll you're going to run out of memory. This can easily be 1000+ images, and using fullResolutionImage will get the largest version of the image.
To resolve this, instead of composing an array of UIImage's, put the ALAsset in the array. Then create the UIImage from the ALAsset only when it's required on screen.

Answer 2

You are storing all 1000+ UIImage in an array and you are out of memory. I have the same issue, mine was 2000+ images and using the implementation below works for me.
I also suggest, you use [asset thumbnail] when displaying images especially if it's just for UITableViewCell or for other purposes that do not require the full resolution of the image.
Here a solution:
//First you need to declare `ALAssetsLibrary *al` as a global variable in the class
//
//like this:
//
//.h
#interface YOURCLASS : UIViewController
{
ALAssetsLibrary *al;
}
#end
//
//or inside your .m
//
#interface YOURCLASS ()
{
ALAssetsLibrary *al;
}
---
// you need to do this to check if 'al' is already declared and to declare once
if (al == nil)
al = [[ALAssetsLibrary alloc] init];
[al enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop)
{
...
[group enumerateAssetsUsingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop)
{
if (asset)
{
/*//your code
UIImage *img=[self imageForAsset:asset];
[arrImages addObject:img];
*/
//instead of storing the actual UIImage object just store the `asset` in your array
//like
[arrImages addObject:asset];
}
}];
...
}
failureBlock:^(NSError *error)
{
// User did not allow access to library
NSLog(#"error");
}];
In your table delegate cellForRowAtIndexPath
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
...
//you need to get the image using the stored asset
//like:
//cast what's inside the array
ALAsset *asset = (ALAsset *)self.arrGroups[indexPath.row];
//self.arrGroups[indexPath.row];
//if just for example i dont know how you access your datas
cell.imageView.image = [UIImage imageWithCGImage:[asset thumbnail]];
//getting the full resolution of the image
//[UIImage imageWithCGImage:[[asset defaultRepresentation] fullResolutionImage]]
//
//or you can simply use what you already have `[self imageForAsset:asset]`
//cell.imageView.image = [self imageForAsset:asset];
...
}
Hope is is helpful for you, Cheers!

Answer 3

-(void)loadCameraPhotos{
[MBProgressHUD showHUDAddedTo:self.view animated:YES];
ALAssetsLibrary *al = [[ALAssetsLibrary alloc] init];
[al enumerateGroupsWithTypes:ALAssetsGroupAll
usingBlock:^(ALAssetsGroup *group, BOOL *stop)
{
NSMutableArray *arrImages=[[NSMutableArray alloc]init];
NSString *albumName = [group valueForProperty:ALAssetsGroupPropertyName];
if (albumName !=nil) {
[arrGroupsNames addObject:albumName];
[group enumerateAssetsUsingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop)
{
if (asset)
{
// if (arrImages.count<7) {
//UIImage *img=[self imageForAsset:asset];
[arrImages addObject:asset];
//}else
// *stop=YES;
}
}
];
[arrGroups addObject:arrImages];
}
[MBProgressHUD hideAllHUDsForView:self.view animated:YES];
[self.tableVieww reloadData];
}
failureBlock:^(NSError *error)
{
// User did not allow access to library
NSLog(#"error");
}
];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *cellIdentifier = #"PhotoSelectionTableViewCell";
PhotoSelectionTableViewCell* cell = (PhotoSelectionTableViewCell *) [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"PhotoSelectionTableViewCell" owner:nil options:nil];
for(id currentObject in topLevelObjects) {
if ([currentObject isKindOfClass:[UITableViewCell class] ]){
cell = (PhotoSelectionTableViewCell *)currentObject;
break;
}
}
}
NSArray *arrtemp=[arrGroups objectAtIndex:indexPath.section];
cell.lblTitle.text=[arrGroupsNames objectAtIndex:indexPath.section];
cell.lblCount.text=[NSString stringWithFormat:#"%lu",(unsigned long)arrtemp.count];
ALAsset *asset = (ALAsset *)[arrtemp lastObject];
cell.imgViewThumbnail.image=[UIImage imageWithCGImage:[asset thumbnail]];;
return cell;
}

Answer 4

I really doubt this solution.NSCache must be used if you want too many photos loaded asap you can see the detail in this repository https://github.com/johnil/JFImagePickerController