UIImage not retrieving From NSUserDefaults - ios

Question

In my application I grab an image from a picker and then try to display it in a separate view.
In my MainViewController.m I have
-(void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info
{
[picker dismissViewControllerAnimated:YES completion:^ {
self.image = [info objectForKey:#"UIImagePickerControllerOriginalImage"];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:UIImagePNGRepresentation(self.image) forKey:#"imageKey"];
[defaults synchronize];
PublishViewController *publish = [self.storyboard instantiateViewControllerWithIdentifier:#"Publish"];
[self presentViewController:publish animated:YES completion:nil];
}];
}
I then try to retrieve the image in my PublishViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
NSData *imageData = [[NSUserDefaults standardUserDefaults] objectForKey:#"imageKey"];
UIImage *userImage = [UIImage imageWithData:imageData];
self.image = [[UIImageView alloc] initWithImage:userImage];
}
The image does not show though. Any reason why?

Answer 1

Perhaps your -viewDidLoad in PublishViewController.m is called before the completion block in dismissViewControllerAnimated:completion: and the NSData has not been saved in NSUserDefaults, yet.
You could put the code to load self.image in PublishViewController.m into -ViewDidAppear.
Now that being said I agree with the commenters that NSUserDefaults may not be the best place to store the image data.

Answer 2

Rather than using NSUserDefaults, you are better using NSFileManager to save the image.
Within the pickerController Delegate methods of your MainViewController.m, place the following code -
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
[self dismissViewControllerAnimated:YES completion:nil];
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
NSData *imageData = UIImageJPEGRepresentation(image, 1);
//This code will save your image so you can retrieve it anywhere else within the app.
NSFileManager *manager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDirectory = [paths objectAtIndex:0];
NSString *fullPath = [documentDirectory stringByAppendingPathComponent:#"yourImageName.jpg"];
[manager createFileAtPath:fullPath contents:imageData attributes:nil];
}
Where you can save the image name to whatever you like
Then within the viewDidLoad of your PublishViewController.m place this code to retrieve the image -
-(void)viewDidLoad{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:#"yourImageName.jpg"];
UIImage *retrievedImage = [UIImage imageWithContentsOfFile:fullPath];
self.yourImageView.image = retrievedImage;
}
Place a UIImageView on the view controller of your PublishViewController, which I've called yourImageView, for this example.
This will work for what you're looking for, hope it helps.
Thanks, Jim.