UIImagePickerController - Save and Load Image? - iphone

Question

There seems to be a scatter of info on this topic, but it seems rather a muddle, so I hoe you don't mind me asking.
I have a UIImagePickerController working, letting me either take a photo or pick on from the library and then set a UIImageView of my choice to show that image taken/selected.
However, how can I firstly save the image, then load it back in when the application is reopened? Also, I will be saving multiple images so they need to be uniquely identified.
Any help will be massively appreciated, thanks.

Answer 1

I don't know of a way to get the Photo from the Photo Album a Second time. There does not seem to be a way to retrieve it again. We do a few things to save the Image internally.
We either convert the Image to NSData and save it in CoreData, or we save it off to our sandbox.
here is a snip of code that we use, this is doing one of a few things, I'm getting the Image from a ScreenShot, though its the same once you have the UIImage.
// go get our screenshot
UIImage* screenShot = [self createScreenShotThumbnailWithWidth:200];
// Save screen shot as a png in the documents directory with the UUID of the IoCDScreen
// Saving to Sandbox
[self saveImage:screenShot withName:currentScreen.itemUUID];
// save image to Photo Album - though you can't get a ref back to it
UIImageWriteToSavedPhotosAlbum(screenShot, self, nil, nil);
//convert our screen shot PNG to NSData and store it in a CoreData Managed Object
currentScreen.screenImageDevelopment = [NSData dataWithData: UIImagePNGRepresentation( screenShot )];
Helper Functions used above
//--------------------------------------------------------------------------------------------------------
// saveImage:withName:
// Description: Save the Image with the name to the Documents folder
//
//--------------------------------------------------------------------------------------------------------
- (void)saveImage:(UIImage *)image withName:(NSString *)name {
//grab the data from our image
NSData *data = UIImageJPEGRepresentation(image, 1.0);
//get a path to the documents Directory
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
// Add out name to the end of the path with .PNG
NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"%#.png", name]];
//Save the file, over write existing if exists.
[fileManager createFileAtPath:fullPath contents:data attributes:nil];
}
//--------------------------------------------------------------------------------------------------------
// createScreenShotThumbnailWithWidth
// Description: Grab a screen shot and then scale it to the width supplied
//
//--------------------------------------------------------------------------------------------------------
-(UIImage *) createScreenShotThumbnailWithWidth:(CGFloat)width{
// Size of our View
CGSize size = self.view.bounds.size;
//First Grab our Screen Shot at Full Resolution
UIGraphicsBeginImageContext(size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//Calculate the scal ratio of the image with the width supplied.
CGFloat ratio = 0;
if (size.width > size.height) {
ratio = width / size.width;
} else {
ratio = width / size.height;
}
//Setup our rect to draw the Screen shot into
CGRect rect = CGRectMake(0.0, 0.0, ratio * size.width, ratio * size.height);
//Scale the screenshot and save it back into itself
UIGraphicsBeginImageContext(rect.size);
[screenShot drawInRect:rect];
screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//Send back our screen shot
return screenShot;
}