Question

I have a modal which displays a UIImagePicker and allows the user to take a photo which then gets put into a UIImageView.

Every now and then I get a memory warning ‘Received Memory Warning’ and the UIImageView does not get assigned. The App is fairly simple and it’s not using a lot of memory, and it seems that a lot of the time this has to do with the ImagePicker as a separate process. This only happens when using the camera, and it happens about one in five times.

There’s a lot of talk about this online, and most of the answers say to ‘handle the warning appropriately’; but I”m not sure what that means – I just want the taken photo to show up in the ImageView! It seems to happen before I can do anything about it in the UIImagePicker delegate.

What can I do to mitigate this?

Here’s the didFinishPickingImage Delegate:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)selectedImage editingInfo:(NSDictionary *)editingInfo {
    //set background for image select button, put image reference somewhere to copy image to documents folder and insert into modular's sentence object.
    //ImagePicker.jpg needs it's border set to 1px black.

    NSLog(@"imagePickerController: selectedimage: %@", selectedImage);

    imageViewBehindPhotoBigButton.clipsToBounds = YES;
    [imageViewBehindPhotoBigButton.layer setBorderColor: [[UIColor blackColor] CGColor]];
    [imageViewBehindPhotoBigButton.layer setBorderWidth: 1.0];
    [imageViewBehindPhotoBigButton setBackgroundColor:[UIColor whiteColor]];

    [imageViewBehindPhotoBigButton setContentMode: UIViewContentModeScaleAspectFill];
    imageViewBehindPhotoBigButton.image = selectedImage;

    imageViewBehindPhotoBigButton.hidden = NO;
    [choosePhotoBigButton setBackgroundImage:nil forState:UIControlStateNormal];

    choosePhotoBarImage.hidden = NO; 
    choosePhotoText.hidden = NO;

    addButton.enabled = YES;

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {      
        //because iPad uses a pop up - we don't want to dismiss modals here!
        [imagePopupController dismissPopoverAnimated:YES];

    }else{
        [self dismissModalViewControllerAnimated:YES];    
    }



}

Answer 1

The answer was to implement threading when scaling / handling the image from the UIImagePickerController. There’s a really good discussion that I used here.