我使用Core Data
来保存我从UIImagePickerController
获取的UIImage(源类型=图像库)。我然后放置或者宁愿将照片放在UICollectionViewCell
中,请帮忙检查一下我做错了什么。
这是我的UIImagePickerController
,由代表调用。
-(void)requestAddScreen {
_picker = [[UIImagePickerController alloc] init];
_picker.delegate = self;
_picker.allowsEditing = NO;
_picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[self presentViewController:_picker animated:YES completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo
{
AppDelegate *delegate = [UIApplication sharedApplication].delegate;
NSManagedObjectContext *context = [delegate managedObjectContext];
NSEntityDescription* entityDescription = [NSEntityDescription entityForName:@"Screen" inManagedObjectContext:context];
Screen* newScreen = [[Screen alloc] initWithEntity:entityDescription insertIntoManagedObjectContext:context];
NSData *imageData = UIImagePNGRepresentation(image);
newScreen.image = imageData;
[_project addProjectScreensObject:newScreen];
NSError *error;
[context save:&error];
if (![context save:&error]) {
NSLog(@"Whoops %@ %@", error, [error localizedDescription]);
}
[self dismissViewControllerAnimated:_picker completion:^{
[_collectionView reloadData];
}];
}
这是我的ViewWillAppear。这是我从Core Data获取数据的地方,ID是正确吗?
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:nil];
AppDelegate *delegate = [UIApplication sharedApplication].delegate;
NSManagedObjectContext *context = [delegate managedObjectContext];
//load project
NSFetchRequest *fetch = [[NSFetchRequest alloc]init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Project" inManagedObjectContext:context];
[fetch setEntity:entity];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"name == %@", @"EMO-KIT"];
[fetch setPredicate:predicate];
NSError *error;
NSArray *array = [context executeFetchRequest:fetch error:&error];
if (array.count == 1) {
_project = array[0];
} else {
_project = [NSEntityDescription insertNewObjectForEntityForName:@"Project" inManagedObjectContext:context];
[_project setValue:@"EMO-KIT" forKey:@"name"];
}
NSArray* screens = [[_project projectScreens] array];
NSIndexPath *bottomIndexPath=[NSIndexPath indexPathForRow:screens.count inSection:0];
[self.collectionView scrollToItemAtIndexPath: bottomIndexPath atScrollPosition:UICollectionViewScrollPositionRight animated:YES];
}
答案 0 :(得分:2)
您可以将UIImage转换为NSData并保存到Core Data中,如下所示
保存
NSData * imageData = UIImagePNGRepresentation(image);
[newsObj setValue:imageData forKey:@"Image"];
检索
UIImage *image = [UIImage imageWithData:[screenObj valueForKey:@"Image"]];
希望它可以帮助你..