unable to save an NSMutableArray of image using persistent storage

Question

I am trying to store an NSMutableArray of images using persistive storage but it is not storing it

here is my code

[imagingList addObject:image ];  //image is of type UIImage
imagingHistory=[NSUserDefaults standardUserDefaults];
[imagingHistory        setObject:imagingList          forKey:@"imaging history"  ];

and in my view did load I write

 imagingList      = [[NSUserDefaults standardUserDefaults] mutableArrayValueForKey:@"imaging history"  ];

when I re-load the application the list of objects is set back to Zero

am I missing something ?

Answer 1

You can't save a UIImage directly in the user defaults. You have to convert it to an NSData first. Just by chance, when I was looking for the NSUserDefaults reference page to answer this question, a found a tutorial on how to do exactly what you want.

Answer 2

Hmm you really shouldn't be trying to save UIImages into NSUserDefaults. Take a look at this resource https://discussions.apple.com/thread/1729849?start=0&tstart=0 it explains how to get the NSData of the image and write it to a file. From there you can save a reference (NSURL or NSString) to the image's path in your app's document directory and you can load it from there using something like UIImage aImage = [UIImage imageWithData:[NSData datWithContentsOfURL:pathURL]].

Hope that helps.