UIImage gets released at the end the function after assignment has been made

Question

I have a ViewController that holds a custom UIView as its member like this: @property (nonatomic, strong) IBOutlet ProfileUIView * profileUIView;
in my ViewController i get back a UIImage from an imagePickerController:didFinishPickingMediaWithInfo: and there i'm assigning the UIImage i get to a local UIImage variable in my ProfileUIView. i see that the UIImage variable get assigned, but, after the set function ends the UIImage variable get nil and i loose the image somehow.

here is a snippet of imagePickerController:didFinishPickingMediaWithInfo: that's in my ViewController:

NSString *mediaType = info[UIImagePickerControllerMediaType];
[self dismissViewControllerAnimated:NO completion:nil];

if ([mediaType isEqualToString:(NSString *) kUTTypeImage]) {

    [self.profileUIView setPicture:info[UIImagePickerControllerOriginalImage]];

    if (_newMedia)
        UIImageWriteToSavedPhotosAlbum(self.profileImage, self, @selector(image:finishedSavingWithError:contextInfo:), nil);
}

here is the implementation of setPicture:(UIImage *)image: inside my UIView:

self.profilePic = image;    
[self.pictureButton setBackgroundImage:image forState:UIControlStateNormal];

how can i fix it?
thanks!

Dennis Dennis · Accepted Answer · 2015-03-11T11:32:11

ViewController.h

Here we make sure to import the right frameworks, hold a UIImage and the ProfileUIView instance. We also declare a method to pick an image, which can be invoked, e.g., from a button on the corresponding view, when connected in Interface Builder:

#import <UIKit/UIKit.h>
#import <AssetsLibrary/AssetsLibrary.h>
#import <MobileCoreServices/MobileCoreServices.h>
#import "ProfileUIView.h"


@interface ViewController : UIViewController<UIImagePickerControllerDelegate, UINavigationControllerDelegate>

@property (nonatomic, strong) UIImage *profilePic;
@property (strong, nonatomic) IBOutlet ProfileUIView *profileUIView;
- (IBAction)pickImage:(id)sender;

@end

In ViewController.m we implement the method to pick an image and the delegate method that is invoked once the user has picked an image:

- (IBAction)pickImage:(id)sender {
    UIImagePickerController *pickerC = [[UIImagePickerController alloc] init];
    pickerC.delegate = self;
    [self presentViewController:pickerC animated:YES completion:nil];
}

#pragma mark - UIImagePicker delegate methods
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    [self dismissViewControllerAnimated:NO completion:nil];
    NSString *mediaType = info[UIImagePickerControllerMediaType];
    if ([mediaType isEqualToString:(NSString *) kUTTypeImage]) {
        self.profilePic = [info objectForKey:UIImagePickerControllerOriginalImage];
        [self.profileUIView setPicture:self.profilePic];
    }
}

ProfileUIView.h

Here we declare the profile picture UIImage, the UIButton which shows the picture, and the method that sets the image:

#import <UIKit/UIKit.h>

@interface ProfileUIView : UIView

@property (nonatomic, retain) UIImage *profilePic;
@property (strong, nonatomic) IBOutlet UIButton *pictureButton;

- (void) setPicture:(UIImage *)image;

@end

ProfileUIView.m

Here we make sure that the UIButton is in place when we awake from NIB, and implement the set picture method to set the image as background of the UIButton:

#import "ProfileUIView.h"

@implementation ProfileUIView

-(void)awakeFromNib {
    self.pictureButton = [[UIButton alloc] initWithFrame:self.bounds];
    [self addSubview:self.pictureButton];
}

- (void) setPicture:(UIImage *)image {
    self.profilePic = image;
    [self.pictureButton setBackgroundImage:image forState:UIControlStateNormal];
}

@end

When pickImage is invoked on the main UIViewController, it stores the image from UIImagePicker into the profilePic property on the UIViewController and assigns the image using the original setPicture method.

UIImage gets released at the end the function after assignment has been made

1 Answers