iOS UIImagePickerController在ios 6上出现奇怪的崩溃

Question

In my app i'm trying to make a single picture using the camera, but it crashes all the time for no reason.

I'm dealing with this problem for long now, so i'm providing code that can seem unnecessary: in the viewcontroller:

- (id) init
{
    if([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)
    {
        self = [super initWithNibName:@"WCAddNewWatchViewController_iPhone" bundle:[NSBundle mainBundle]];
    }else
    {
        self = [super initWithNibName:@"WCAddNewWatchViewController_iPad" bundle:[NSBundle mainBundle]];
    }

    if(self)
    {

    }

    return self;
}
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.

    [[self navigationItem]setRightBarButtonItem:self.AddButton];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)ChangeImageButtonTapped:(id)sender {
    UIImagePickerController* picker = [[UIImagePickerController alloc] init];

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;
    }
    else
    {
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    }

    picker.mediaTypes = @[(NSString *) kUTTypeImage];
    picker.allowsEditing = NO;
    [picker setDelegate:self];

    [self presentViewController:picker animated:YES completion:nil];

}

#pragma mark UIImagePickerControllerDelegate

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

    NSString *mediaType = info[UIImagePickerControllerMediaType];

    [self dismissViewControllerAnimated:YES completion:nil];

    if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
        UIImage *image = info[UIImagePickerControllerOriginalImage];
        selectedImage = image;
     //   self.watchImageView.image = selectedImage;

    }

    NSLog(@"no crash!!!!"); //that's a lie...
}

There's no crash message, the log writes that the app received memory warnings, then crashes. The device log says:

TIL the out-of-memory killer is called "jetsam" on iOS

Can anyone look at my code and tell me what am I doing wrong?

Answer 1

you got killed by the watchdog process because you didnt handle memory warnings (ios has process that monitors mem usage & app startup time and kills apps that appear to go rogue')

btw: TIL = Today I learned :D

use a scaled down version of the image for display.

- (UIImage *)scaledCopyOfSize:(CGSize)newSize {
    CGImageRef imgRef = self.CGImage;

    CGFloat width = CGImageGetWidth(imgRef);
    CGFloat height = CGImageGetHeight(imgRef);

    CGAffineTransform transform = CGAffineTransformIdentity;
    CGRect bounds = CGRectMake(0, 0, width, height);
    if (width > newSize.width || height > newSize.height) {
        CGFloat ratio = width/height;
        if (ratio > 1) {
            bounds.size.width = newSize.width;
            bounds.size.height = bounds.size.width / ratio;
        }
        else {
            bounds.size.height = newSize.height;
            bounds.size.width = bounds.size.height * ratio;
        }
    }

    CGFloat scaleRatio = bounds.size.width / width;
    CGSize imageSize = CGSizeMake(CGImageGetWidth(imgRef), CGImageGetHeight(imgRef));
    CGFloat boundHeight;
    UIImageOrientation orient = self.imageOrientation;
    switch(orient) {

        case UIImageOrientationUp: //EXIF = 1
            transform = CGAffineTransformIdentity;
            break;

        case UIImageOrientationUpMirrored: //EXIF = 2
            transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
            transform = CGAffineTransformScale(transform, -1.0, 1.0);
            break;

        case UIImageOrientationDown: //EXIF = 3
            transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;

        case UIImageOrientationDownMirrored: //EXIF = 4
            transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
            transform = CGAffineTransformScale(transform, 1.0, -1.0);
            break;

        case UIImageOrientationLeftMirrored: //EXIF = 5
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.width);
            transform = CGAffineTransformScale(transform, -1.0, 1.0);
            transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
            break;

        case UIImageOrientationLeft: //EXIF = 6
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
            transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
            break;

        case UIImageOrientationRightMirrored: //EXIF = 7
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeScale(-1.0, 1.0);
            transform = CGAffineTransformRotate(transform, M_PI / 2.0);
            break;

        case UIImageOrientationRight: //EXIF = 8
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
            transform = CGAffineTransformRotate(transform, M_PI / 2.0);
            break;

        default:
            [NSException raise:NSInternalInconsistencyException format:@"Invalid image orientation"];

    }

    if (UIGraphicsBeginImageContextWithOptions) {
        UIGraphicsBeginImageContextWithOptions(bounds.size, NO,
                                               /* 0.0f will scale to 1.0/2.0 depending on if the
                                                device has a high-resolution screen */
                                               0.0f);
    } else {
        UIGraphicsBeginImageContext(bounds.size);
    }

    CGContextRef context = UIGraphicsGetCurrentContext();

    if (orient == UIImageOrientationRight || orient == UIImageOrientationLeft) {
        CGContextScaleCTM(context, -scaleRatio, scaleRatio);
        CGContextTranslateCTM(context, -height, 0);
    }
    else {
        CGContextScaleCTM(context, scaleRatio, -scaleRatio);
        CGContextTranslateCTM(context, 0, -height);
    }

    CGContextConcatCTM(context, transform);

    CGContextDrawImage(context, CGRectMake(0, 0, width, height), imgRef);
    UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return imageCopy;
}