This is not possible. The UIImagePickerController will give you a UIImage*
, and you have to convert it into NSData
yourself, and store it in your local sandbox. There is no SDK-approved way to access the images in the user's photo gallery (for security reasons).
Assuming you're using SDK 3.0, here is a function on the return of the picker that will save it to the disk, in your application's documents directory (this should work, though I may have a small mistake somewhere):
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
// Dismiss the picker
[[picker parentViewController] dismissModalViewControllerAnimated:YES];
// Get the image from the result
UIImage* image = [info valueForKey:@"UIImagePickerControllerOriginalImage"];
// Get the data for the image as a PNG
NSData* imageData = UIImagePNGRepresentation(image);
// Give a name to the file
NSString* imageName = "MyImage.png";
// Now, we have to find the documents directory so we can save it
// Note that you might want to save it elsewhere, like the cache directory,
// or something similar.
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* documentsDirectory = [paths objectAtIndex:0];
// Now we get the full path to the file
NSString* fullPathToFile = [documentsDirectory stringByAppendingPathComponent:imageName];
// and then we write it out
[imageData writeToFile:fullPathToFile atomically:NO];
return;
}