Search code examples
iosobjective-ccore-datansdata

Convert UIImage to NSData and save with core data


I have a UIImageView whose image gets set via UIImagePicker

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
    [picker dismissViewControllerAnimated:YES completion:nil];
    self.gImage.image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
}

I "attempt" to convert this image to NSData and save it with core data:

NSData *imageData = UIImagePNGRepresentation(self.gImage.image);
NSString *savedData = [[NSString alloc]initWithData:imageData encoding:NSUTF8StringEncoding];

//am is a pointer to my entities class. imageData is just a NSString attribute
am.imageData = savedData;

NSError *error;
if (![self.managedObjectContext save:&error]) {
    //Handle Error
} else {
    [self dismissViewControllerAnimated:YES completion:nil];
}

Then I try to load the image in a separate file:

self.cell.gImage.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:self.myEntity.imageData]]];

I cannot see why this is not working. Any help is greatly appreciated!


Solution

  • You can convert a UIImage to NSData like this:

    If PNG image

    UIImage *image = [UIImage imageNamed:@"imageName.png"];
    NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(image)];
    

    If JPG image

    UIImage *image = [UIImage imageNamed:@"imageName.jpg"];
    NSData *imageData = UIImageJPEGRepresentation(image, 1.0);
    

    You can store it in CoreData like so (this is one possible useful solution):

    [newManagedObject setValue:imageData forKey:@"image"];
    

    You can load the data from CoreData like this:

    NSManagedObject *selectedObject = [[self yourFetchCOntroller] objectAtIndexPath:indexPath];
    UIImage *image = [UIImage imageWithData:[selectedObject valueForKey:@"image"]];
    
    // Set the image to your image view  
    yourimageView.image = image;