从照片库导入图像时出现内存泄漏

Question

i am having a memory problem with importing photos from the camera roll. I am using storyboard and ARC (automatic reference counting). when I import the 3rd or 4th photo the app crashes, and in fact instruments shows under free physical memory that there is no memory left. I tried using @autoreleasepools but it does not seem to work:

- (void)viewDidLoad {
@autoreleasepool {
[super viewDidLoad];

UIBarButtonItem *cameraButton = [[UIBarButtonItem alloc]
                                 initWithTitle:@"Camera"
                                 style:UIBarButtonItemStyleBordered
                                 target:self
                                 action:@selector(useCamera:)];

UIBarButtonItem *cameraRollButton = [[UIBarButtonItem alloc] 
                                     initWithTitle:@"Camera Roll"
                                     style:UIBarButtonItemStyleBordered
                                     target:self
                                     action:@selector(useCameraRoll:)];
NSArray *items = [NSArray arrayWithObjects: cameraButton,
                  cameraRollButton, nil];
[toolbar setItems:items animated:NO];

mouseMoved = 0;

}}

 - (IBAction) useCamera: (id)sender
 {
if ([UIImagePickerController isSourceTypeAvailable:
     UIImagePickerControllerSourceTypeCamera])
{
    UIImagePickerController *imagePicker =
    [[UIImagePickerController alloc] init];
    imagePicker.delegate = self;
    imagePicker.sourceType =
    UIImagePickerControllerSourceTypeCamera;
    imagePicker.mediaTypes = [NSArray arrayWithObjects:
                              (NSString *) kUTTypeImage,
                              nil];
    imagePicker.allowsEditing = NO;
    [self presentModalViewController:imagePicker
                            animated:YES];

    newMedia = YES;

    }else{
    NSLog(@"Camera is not available");
    UIAlertView *alert1 = [[UIAlertView alloc] initWithTitle:@"Important message" message:@"Unfortunately the camera is not available on your device." delegate:self cancelButtonTitle:@"Ok" otherButtonTitles: nil];
    [alert1 show];
}

}

 - (IBAction) useCameraRoll: (id)sender
{
@autoreleasepool {

    if ([self.popoverController isPopoverVisible]) {
    [self.popoverController dismissPopoverAnimated:YES];

    } else{

    }{
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypeSavedPhotosAlbum])
    {
        @autoreleasepool {

        UIImagePickerController *imagePicker =
        [[UIImagePickerController alloc] init];

        imagePicker.delegate = self;
        imagePicker.sourceType =
        UIImagePickerControllerSourceTypePhotoLibrary;
        imagePicker.mediaTypes = [NSArray arrayWithObjects:
                                  (NSString *) kUTTypeImage,
                                  nil];

        imagePicker.allowsEditing = YES;

        self.popoverController = [[UIPopoverController alloc]
                                  initWithContentViewController:imagePicker];
        }
        popoverController.delegate = self;

        [self.popoverController 
         presentPopoverFromBarButtonItem:sender
         permittedArrowDirections:UIPopoverArrowDirectionUp
         animated:YES];


        newMedia = NO;
    }}
}
 }

-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [self.popoverController dismissPopoverAnimated:true];
    @autoreleasepool {


NSString *mediaType = [info
                       objectForKey:UIImagePickerControllerMediaType];

    if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
    UIImage *image = [info
                      objectForKey:UIImagePickerControllerOriginalImage];

    image1.image = image;
    if (newMedia)
        UIImageWriteToSavedPhotosAlbum(image,
                                       self,  
                                          @selector(image:finishedSavingWithError:contextInfo:),
                                       nil);
}
else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])
{
    // Code here to support video if enabled
}}
}

-(void)image:(UIImage *)image
finishedSavingWithError:(NSError *)error
 contextInfo:(void *)contextInfo
{
if (error) {
    UIAlertView *alert = [[UIAlertView alloc]
                          initWithTitle: @"Save failed"
                          message: @"Failed to save image"\
                          delegate: nil
                          cancelButtonTitle:@"OK"
                          otherButtonTitles:nil];
    [alert show];
}
}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{

}

please help!! thanks in advance.

Answer 1

Have same issue. Using 2-3 MB for each new item created. Responsible caller = CGDataProviderCreateWithCopyOfData

Had to set

imagePicker.allowsEditing = NO;

It seems that when using editing the image, this does not release properly.

Answer 2

How does image1.image handle ownership.

Use Heapshot to find where/how the memory is lost: For HowTo use Heapshot to find memory creap, see: bbum blog

Basically there method is to run Instruments allocate tool, take a heapshot, run an intuition of your code and another heapshot repeating 3 or 4 times. This will indicate memory that is allocated and not released during the iterations.

To figure out the results disclose to see the individual allocations.

If you need to see where retains, releases and autoreleases occur for an object use instruments:

Run in instruments, in Allocations set "Record reference counts" on on (you have to stop recording to set the option). Cause the picker to run, stop recording, search for there ivar (datePickerView), drill down and you will be able to see where all retains, releases and autoreleases occurred.