使用彈出窗口在prepareForSegue中設置屬性

Question

我有一個ViewController，它在Interface Builder中創建了幾個按鈕。第一個按鈕將顯示在IB中鏈接的彈出式窗口，它鏈接到UINavigationController並在其下有一個類別爲PopupViewController的TableView。

第二個按鈕，我有一個動作設置爲goToCategory和上點擊的時候，我想設置在PopupViewController

ViewController.m 
//go to category 
-(IBAction)goToCategory:(id)sender{ 
    NSLog(@"GO TO CAT"); 
    //PopupViewController *popupVC = [self.storyboard instantiateViewControllerWithIdentifier:@"popoverVC"]; 
    //popupVC.currentLevel = 1; 
    [self performSegueWithIdentifier:@"popoverSegue" sender:self]; 
} 

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{ 
    NSLog(@"seg1"); 
    if ([[segue identifier] isEqualToString:@"popoverSegue"]){ 
     //PopupViewController *popupVC = (PopupViewController *)[[segue destinationViewController] visibleViewController]; 
     //PopupViewController *popupVC = [segue destinationViewController]; 
     PopupViewController *popupVC=[[[segue destinationViewController]viewControllers]objectAtIndex:0]; 
     popupVC.test = @"just a test"; 
     NSLog(@"seg2"); 
    } 
} 

PopupViewController.h 
@property (nonatomic, strong) NSString *test; 

PopupViewController.m 
@synthesize test; 
-(void)viewDidLoad{ 
    NSLog(@"test: %@", test); //returns test: (null) 
} 

屬性我發現了很多SO答案，因此一些在我的prepareForSegue中註釋掉的線條。但是這些都沒有設定值test。 PopupViewController *popupVC = [segue destinationViewController];由於引用了UINavigationController而引發錯誤，所以我不能直接使用它，即使這似乎是在我見過的很多答案中做到的。但是不管我嘗試用哪種方式做，輸出總是空的？

UPDATE：

PopupViewController *popupVC = (PopupViewController *)[[segue destinationViewController] visibleViewController];和PopupViewController *popupVC=[[[segue destinationViewController]viewControllers]objectAtIndex:0];從我prepareForSegue在6.1模擬器都工作上面。我的iPad的iOS是5.1.1，它不工作。我需要爲iOS 5做些什麼不同嗎？

Answer 1

試試這個

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender 
{ 
    NSLog(@"seg1"); 
    if ([[segue identifier] isEqualToString:@"popoverSegue"]) 
    { 
     UINavigationController *navController = (UINavigationController*)[segue destinationViewController]; 
     PopupViewController *popupVC = [navController topViewController]; 
     popupVC.test = @"just a test"; 
     NSLog(@"seg2"); 
    } 
}