0
我需要幫助！^^目標C核心數據 - 屬性不會被保存持久
我在屬性（名稱，女士prename）的人的兩個名字，並保存它們寫。如果我嘗試在另一個視圖中訪問attrubutes，那麼它們是零。我不明白爲什麼？！？
我這樣做了。我使用getProfile方法獲取profileContext，並使用Dot-Notation訪問屬性，然後保存它。我的NSLog顯示我正確的名字和我的提取。
ownProfile = [[MyProfile alloc] init];
profileContext = [ownProfile getProfile];
ownProfile = (MyProfile*)[NSEntityDescription insertNewObjectForEntityForName:@"MyProfile" inManagedObjectContext:profileContext];
ownProfile.Vorname = @"Max";
ownProfile.Nachname = @"Wilson";
NSLog(@"%@",ownProfile.Nachname);
if ([profileContext hasChanges]) {
NSLog(@"It has changes!");
[profileContext save:nil];
}
//Fetching
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"MyProfile" inManagedObjectContext:profileContext];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:entityDescription];
NSArray *array = [profileContext executeFetchRequest:request error:nil];
for (int i=0; i < [array count]; i++) {
MyProfile *object = [array objectAtIndex:i];
NSLog(@"Name: %@",object.Nachname);
}
如果我嘗試訪問另一個ViewController子類中的屬性，它們是零。這是代碼：
- (void)viewDidLoad {
[super viewDidLoad];
ownProfile = [[MyProfile alloc] init];
NSManagedObjectContext *profileContext = [ownProfile getProfile];
ownProfile = [NSEntityDescription insertNewObjectForEntityForName:@"MyProfile" inManagedObjectContext:profileContext];
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"MyProfile" inManagedObjectContext:profileContext];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:entityDescription];
[request setIncludesPropertyValues:NO]; //only fetch the managedObjectID
NSArray *array = [profileContext executeFetchRequest:request error:nil];
[request release];
MyProfile *object = [array objectAtIndex:[array count]-1];
NSLog(@"%@",object);
}
我getProfile方法是在NSManagedObjectClass，看起來像這樣：
-(NSManagedObjectContext*) getProfile {
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES],
NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES],
NSInferMappingModelAutomaticallyOption, nil];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
NSLog(@"basePath = %@",basePath);
NSURL *storeUrl = [NSURL fileURLWithPath:[basePath stringByAppendingFormat:@"CoreData.sqlite"]];
NSPersistentStoreCoordinator *persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[NSManagedObjectModel mergedModelFromBundles:nil]];
NSLog(@"PersistentStore = %@",persistentStoreCoordinator);
NSError *error = nil;
if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error]) {
NSLog(@"error loading persistent store..");
[[NSFileManager defaultManager] removeItemAtPath:storeUrl.path error:nil];
if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
NSManagedObjectContext *profile = [[NSManagedObjectContext alloc] init];
[profile setPersistentStoreCoordinator:persistentStoreCoordinator];
return profile;
}
請幫幫我！^^