How to save a new-token photo in IOS - ios

Question

I'm now struggling with UIImagePicker.
I've read the document but it seems not to mention how should I save a newly token photo, I mean save it into my own documents in my app.
In fact, there is a "photo" attribute in one of my entity in core data,
so, the "photo" should just be a NSString to save the real photo's file path, right?
But how to save that photo and get its correct file path?
I just know little about NSFilePath or something like that, hope someone to teach me a little bit.
Thanks a lot!

Answer 1

You may know how to present the image picker:
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
[viewController presentModalViewController:picker animated:YES];
With the above the viewController implements the UIImagePickerControllerDelegate and make sure you implement this function:
- (void)imagePickerController:(UIImagePickerController *)returnedPicker didFinishPickingMediaWithInfo:(NSDictionary *)info
and
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)returnedPicker
The first method is called when user has picked a photo. In this method you get the image using:
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
To write this to a file you can make it a JPEG or a PNG. If a JPEG you may do this:
[UIImageJPEGRepresentation(image, 1.0) writeToFile:filename atomically:YES];
You just need to set the filename.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsDir = [paths objectAtIndex:0];
NSString *filename = [docsDir stringByAppendingPathComponent:#"myFilename.jpg"];
To get the image back into a UIImage you do this:
NSData *data = [NSData dataWithContentsOfFile:filename;
if(data != nil)
UIImage *image = [UIImage imageWithData:data];