不能通過一個數據對象視圖控制器視圖控制器內

Question

我不知道爲什麼，但我有一個傳遞數據對象（NSManagedObject）的視圖控制器故障時視圖控制器正在內的另一個實例一。在傳遞對象之前記錄對象時，它具有其所有數據，但在到達視圖控制器後，它是空的。看起來這應該是相當直接的，但由於某種原因，它只是沒有到達那裏。

其中NSManagedObject分配給在實現文件的接受視圖控制器中的代碼是：viewController.thisCard = ACARD;

任何幫助，非常感謝。提前致謝。

這是視圖控制器的標題，該標題滾動：

@interface HandViewController : UIViewController 
<UIScrollViewDelegate> 
{ 
    IBOutlet UIScrollView *scrollView; 
    IBOutlet UIPageControl *pageControl; 

    BOOL pageControlIsChangingPage; 
    NSManagedObjectContext *context; 
} 

@property (nonatomic, retain) UIView *scrollView; 
@property (nonatomic, retain) UIPageControl *pageControl; 
@property (nonatomic, retain) NSManagedObjectContext *context; 

/* for pageControl */ 
- (IBAction)changePage:(id)sender; 

@end 

這是viewDidLoad中在該對象中

- (void)viewDidLoad 
{ 
    scrollView.delegate = self; 

    [self.scrollView setBackgroundColor:[UIColor blackColor]]; 
    [scrollView setCanCancelContentTouches:NO]; 

    scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite; 
    scrollView.clipsToBounds = YES; 
    scrollView.scrollEnabled = YES; 
    scrollView.pagingEnabled = YES; 

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; 

    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Game" inManagedObjectContext:[self context]]; 
    [fetchRequest setEntity:entity]; 

    NSError *error; 
    NSArray *fetchedGames = [self.context executeFetchRequest:fetchRequest error:&error]; 

    [fetchRequest release]; 

    Game *aGame = [fetchedGames objectAtIndex:0]; 

    CGFloat cx = 0; 

    for (Card *aCard in aGame.turnUpcoming.hand) { 

     CardViewController *viewController = [[CardViewController alloc] initWithNibName:@"CardViewController" bundle:nil]; 

     CGRect rect = self.view.frame; 
     rect.size.height = scrollView.frame.size.height - 50; 
     rect.size.width = scrollView.frame.size.width - 50; 
     rect.origin.x = ((scrollView.frame.size.width - rect.size.width)/2) + cx; 
     rect.origin.y = ((scrollView.frame.size.height - rect.size.height)/2); 
     viewController.view.frame = rect; 
     viewController.thisCard = aCard; 
     [scrollView addSubview:viewController.view]; 

     cx += scrollView.frame.size.width; 

     [viewController release]; 
    } 

    self.pageControl.numberOfPages = [aGame.turnUpcoming.hand count]; 
    [scrollView setContentSize:CGSizeMake(cx, [scrollView bounds].size.height)]; 

    [super viewDidLoad]; 
    // Do any additional setup after loading the view from its nib. 
} 

UPDATE的實現：每請求，我加入一個比特的來自視圖控制器的代碼

這是CardViewController的標頭

@interface CardViewController : UIViewController { 
    UILabel IBOutlet *cardValue; 
    UILabel IBOutlet *cardInstruction; 
    UILabel IBOutlet *cardHint; 
    UILabel IBOutlet *cardTimer; 
    UIButton IBOutlet *playCardButton; 

    Card *thisCard; 
} 

@property (nonatomic, retain) UILabel IBOutlet *cardValue; 
@property (nonatomic, retain) UILabel IBOutlet *cardInstruction; 
@property (nonatomic, retain) UILabel IBOutlet *cardHint; 
@property (nonatomic, retain) UILabel IBOutlet *cardTimer; 
@property (nonatomic, retain) UIButton IBOutlet *playCardButton; 
@property (nonatomic, retain) Card *thisCard; 

@end 

這裏是CardViewController

的執行viewDidLoad中

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    if ([thisCard isObjectValid]) { 
     cardValue.text = [thisCard.value stringValue]; 
    } 

} 

更新：在viewDidLoad中卡環和新CardView代碼如下

循環在viewDidLoad中新的代碼，每個建議：

for (Card *aCard in aGame.turnUpcoming.hand) { 

     CGRect rect = scrollView.frame; 
     rect.size.height = scrollView.frame.size.height - 50; 
     rect.size.width = scrollView.frame.size.width - 50; 
     rect.origin.x = ((scrollView.frame.size.width - rect.size.width)/2) + cx; 
     rect.origin.y = ((scrollView.frame.size.height - rect.size.height)/2); 

     tempCardView = [[CardView alloc] initWithFrame:rect]; 
     tempCardView.thisCard = aCard; 

     NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:@"CardView" owner:self options:nil]; 

     tempCardView = [nibObjects objectAtIndex:0]; 

     [scrollView addSubview:tempCardView]; 

     cx += scrollView.frame.size.width; 

     [tempCardView release]; 
    } 

頭文件CardView.h

@interface CardView : UIView { 
    UILabel IBOutlet *cardValue; 
    UILabel IBOutlet *cardInstruction; 
    UILabel IBOutlet *cardHint; 
    UILabel IBOutlet *cardTimer; 
    UIButton IBOutlet *playCardButton; 

    Card *thisCard; 
} 

@property (nonatomic, retain) UILabel IBOutlet *cardValue; 
@property (nonatomic, retain) UILabel IBOutlet *cardInstruction; 
@property (nonatomic, retain) UILabel IBOutlet *cardHint; 
@property (nonatomic, retain) UILabel IBOutlet *cardTimer; 
@property (nonatomic, retain) UIButton IBOutlet *playCardButton; 
@property (nonatomic, retain) Card *thisCard; 

@end 

實現文件CardView.m

@implementation CardView 

@synthesize cardHint; 
@synthesize cardTimer; 
@synthesize cardValue; 
@synthesize cardInstruction; 
@synthesize playCardButton; 
@synthesize thisCard; 

- (id)initWithFrame:(CGRect)frame 
{ 
    self = [super initWithFrame:frame]; 
    if (self) { 
     if ([thisCard isObjectValid]) { 
      cardValue.text = [thisCard.value stringValue]; 
      cardInstruction.text = thisCard.instruction; 
      cardHint.text = thisCard.hint; 
      cardTimer.text = [thisCard.time stringValue]; 
     } 
    } 
    return self; 
} 

@end 

更新時間：6/16 - 增加XIB屏幕截圖

CardView.xib

Answer 1

好像你CardViewController實際上應該是一個UIView的。隨着蘋果說：「一個單一的視圖控制器通常管理與單一屏幕的價值的內容相關的意見，雖然在iPad上的應用程序，這可能並非總是如此。」

在循環（修改後的UIView），您要創建一個tempCard然後加載另一個。如果您在IB（見下文）相連tempCardView，那麼所有你需要的是：

for (Card *aCard in aGame.turnUpcoming.hand) { 
    CGRect rect; 
    rect.size.width = scrollView.frame.size.width - 50; 
    rect.size.height = scrollView.frame.size.height - 50; 
    rect.origin.x = ((scrollView.frame.size.width - rect.size.width)/2) + cx; 
    rect.origin.y = ((scrollView.frame.size.height - rect.size.height)/2); 
    [[NSBundle mainBundle] loadNibNamed:@"CardView" owner:self options:nil]; //magically connected to tempCardView. 
    self.tempCardView.frame = rect; 
    self.tempCardView.thisCard = aCard; 

    [scrollView addSubview:tempCardView]; 
    cx += scrollView.frame.size.width; 
    self.tempCardView = nil; 
} 

所以，你有兩個XIBs，你的主要一個與您的viewController加載，和一個（CardView），其被加載每張卡一次。

現在，裏面CardView，你想太早建立的標籤。 initWithFrame（在上述情況下被稱爲loadFromNib）期間，您沒有訪問尚未thisCard。你所需要的thisCard一個setter，它會被稱爲值分配給thisCard財產的任何時間：

-(void) setThisCard: (Card *) newCard { 
     if (thisCard == newCard) return; 
     [newCard retain]; 
     [thisCard release]; 
     thisCard = newCard; 
     self.cardValue.text = [thisCard.value stringValue]; 
     self.cardInstruction.text = thisCard.instruction; 
     self.cardHint.text = thisCard.hint; 
     self.cardTimer.text = [thisCard.time stringValue]; 
    } 

現在在Interface Builder，

1. 用單一的UIView與創建CardView.xib ，但將FileOwner設置爲您的VC，而不是CardView，因爲這是誰將加載它（以及誰擁有tempCardView屬性）。
2. 將視圖的類型設置爲CardView，然後將其掛接到FileOwner（又名HandViewController）的tempCardView屬性
3. 將所有其他卡片部件放入該CardView中，並將其掛接到該CardView的屬性。

你應該全部設置。