我有以下代码:
dispatch_async(dispatch_get_main_queue(), ^{
NSManagedObjectContext *localContext = [NSManagedObjectContext contextForCurrentThread];
Item *newItem = [Item createInContext:localContext];
newItem.title = NULL_TO_NIL([itemJson valueForKey:@"title"]);
newItem.image_url = NULL_TO_NIL([itemJson valueForKey:@"image_url"]);
newItem.order_id = @([[self largestOrderId] intValue] + 1);
NSURL *url = [NSURL URLWithString:newItem.image_url];
NSData *data = [[NSData alloc] initWithContentsOfURL: url];
if (data == nil) {
NSLog(@"Image data is nil from %@", url);
} else {
NSLog(@"Image fetched in saveItemFromJson for cid:%@ order_id:%@", newItem.cid, newItem.order_id);
newItem.image = [UIImage imageWithData:data];
}
if (![localContext hasChanges]) {
NSLog(@"No local change detected. Quitting");
return;
}
[localContext saveToPersistentStoreWithCompletion:^(BOOL success, NSError *error) {
if (!success)
NSLog(@"Error: %@", [error localizedDescription]);
else
NSLog(@"Item persisted for cid:%@ order_id:%@", newItem.cid, newItem.order_id);
}];
});
我似乎得到了很多以下内容:
2013-02-13 18:55:47.404 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8386a90) → Saving <NSManagedObjectContext (0x8386a90): *** DEFAULT ***> on *** MAIN THREAD ***
2013-02-13 18:55:47.404 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8386a90) → Save Parents? 1
2013-02-13 18:55:47.404 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8386a90) → Save Synchronously? 0
2013-02-13 18:55:47.497 Giordano.iPhone[13956:c07] Image fetched in saveItemFromJson for cid:7218 order_id:10
2013-02-13 18:55:47.497 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8386a90) → Saving <NSManagedObjectContext (0x8386a90): *** DEFAULT ***> on *** MAIN THREAD ***
2013-02-13 18:55:47.498 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8386a90) → Save Parents? 1
2013-02-13 18:55:47.498 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8386a90) → Save Synchronously? 0
2013-02-13 18:55:47.499 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalRecord) MR_contextWillSave:](0x8386a90) Context DEFAULT is about to save. Obtaining permanent IDs for new 10 inserted objects
2013-02-13 18:55:47.501 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) → Saving <NSManagedObjectContext (0x8385aa0): *** BACKGROUND SAVING (ROOT) ***> on *** MAIN THREAD ***
2013-02-13 18:55:47.502 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) → Save Parents? 0
2013-02-13 18:55:47.502 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) → Save Synchronously? 1
2013-02-13 18:55:47.502 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalRecord) MR_contextWillSave:](0x8385aa0) Context BACKGROUND SAVING (ROOT) is about to save. Obtaining permanent IDs for new 10 inserted objects
2013-02-13 18:55:47.505 Giordano.iPhone[13956:c07] __70-[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:]_block_invoke21(0x8385aa0) → Finished saving: <NSManagedObjectContext (0x8385aa0): *** BACKGROUND SAVING (ROOT) ***> on *** MAIN THREAD ***
2013-02-13 18:55:47.505 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING
带有以下错误消息:
2013-02-13 18:55:47.511 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING
2013-02-13 18:55:47.512 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING
2013-02-13 18:55:47.512 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING
2013-02-13 18:55:47.512 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING
2013-02-13 18:55:47.513 Giordano.iPhone[13956:c07] -[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x8385aa0) NO CHANGES IN ** BACKGROUND SAVING (ROOT) ** CONTEXT - NOT SAVING
2013-02-13 18:55:47.515 Giordano.iPhone[13956:c07] Error: (null)
2013-02-13 18:55:47.515 Giordano.iPhone[13956:c07] Error: (null)
2013-02-13 18:55:47.515 Giordano.iPhone[13956:c07] Error: (null)
我避免使用它,saveInBackgroundWithBlock
因为它已被弃用(文档需要更新?)
关于我的代码有什么问题的任何想法?
更新
我的团队认为现在 MagicalRecord 的 bug 太多了。我们已经将我们的代码从 MR 完全迁移回 CoreData。感谢您的关注。