如何在iOS6的Core Data中保存和檢索兩個數組

Question

我有兩個數組

1. retrievedNamesMutableArray
2. retrievedImagesArray

我保存在核心數據中。 盡管保存操作成功，但是當我獲取數據時，似乎只獲取名稱或圖像，而不是兩者。 我假設我可以在核心數據中存儲NSDictionary，但似乎無法找出一種實現方法。

這就是我要保存到Core Data的操作。

  -(void)saveToPhoneDatabase
{
   AddressBookAppDelegate *appDelegate =[[UIApplication sharedApplication]delegate];
   NSManagedObjectContext *context = [appDelegate managedObjectContext];
   NSManagedObject *newContact;

  /* I assume this can be done but can't figure out proper process.
   NSMutableDictionary *dictionary = [[NSMutableDictionary alloc]init];
  [dictionary setObject:self.retrievedNamesMutableArray forKey:@"NamesArray"];
  [dictionary setObject:self.retrievedImagesArray forKey:@"ImagesArray"];
  */

   for (NSString *object in self.retrievedNamesMutableArray)
   {
    newContact = [NSEntityDescription insertNewObjectForEntityForName:@"AddressBook" inManagedObjectContext:context];
    [newContact setValue:@"GroupOne" forKey:@"groups"];
    [newContact setValue:object forKey:@"firstName"];

   }

   for (UIImage *img in self.retrievedImagesArray)
   {
     newContact = [NSEntityDescription insertNewObjectForEntityForName:@"AddressBook" inManagedObjectContext:context];
     [newContact setValue:img forKey:@"photo"];
     NSLog(@"Saved the photos of Array");
   }

  [context save:nil];
}

這就是我的方法。

-(void)fetchFromPhoneDatabase
{
   AddressBookAppDelegate *appDelegate =[[UIApplication sharedApplication]delegate];
   NSManagedObjectContext *context = [appDelegate managedObjectContext];
   NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"AddressBook" inManagedObjectContext:context];
   NSFetchRequest *request = [[NSFetchRequest alloc] init];
   [request setEntity:entityDesc];
   NSError *error;
   self.arrayForTable = [context executeFetchRequest:request error:&error];

   NSLog(@"contents from core data = %@",self.arrayForTable);

  [self.tableView reloadData];

 }

Answer 1

您的第一個循環創建包含名稱但不包含圖像的對象，而您的第二個循環創建包含圖像但不包含名稱的不同對象。

假設（根據您先前的問題）兩個數組的大小相同，則您應該為每個名稱/圖像僅創建一個對象：

for (NSUInteger i = 0; i < [self.reterivedNamesMutableArray count]; i++) {
    NSString *object = self.reterivedNamesMutableArray[i];
    UIImage *img = self.reterivedImagesArray[i];

    newContact = [NSEntityDescription insertNewObjectForEntityForName:@"AddressBook" inManagedObjectContext:context];
    [newContact setValue:@"GroupOne" forKey:@"groups"];
    [newContact setValue:object forKey:@"firstName"];
    [newContact setValue:img forKey:@"photo"];
}