IBOutlet nil after instantiateViewControllerWithIdentifier

Question

Не уверен, что я здесь делаю неправильно. Я перечислил, что моя проблема и мой код. Хотелось бы получить помощь.

Спасибо!

Проблема:

• VC1 представляет VC2.
• IBOutlets от VC1 теперь нуль.
• VC2 отклоняется обратно в VC1.
• IBOutlets в VC1 все еще ноль.

VC1 загружает сетку изображений из flickR. VC2 имеет контроллер searchBar, когда VC2 отклоняется, он выполняет запрос flickR. Прямо перед моим self.collectionView.reload() терпит неудачу, потому что self.collectionView равна нулю :(

VC1

import UIKit 

class MainViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource { 

@IBOutlet var collectionView: UICollectionView! 
@IBOutlet var searchMask: UIView! 

let api_key = "f87357398a52b80e0c9f76bf94c8ee94" 

var flickResults:NSMutableArray! = NSMutableArray() 
var titleResults:NSMutableArray! = NSMutableArray() 

override func viewDidLoad() { 
    super.viewDidLoad() 
    loadPhotos("Brasil") 
    // Do any additional setup after loading the view. 
} 

override func viewDidAppear(animated: Bool) { 
    super.viewDidAppear(animated) 
} 

func loadPhotos(searchString: String) { 
    let flickr:FlickrHelper = FlickrHelper() 
    println("Collection: \(self.collectionView)") 
    flickr.request(searchString, per_page: 50, completion: { (searchStr, flickrPhotos, photoTitle) ->() in 
     dispatch_async(dispatch_get_main_queue(), { 
      self.flickResults = flickrPhotos 
      self.titleResults = photoTitle 
      self.collectionView.reloadData() 
     }) 
    }) 
} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
} 

override func preferredStatusBarStyle() -> UIStatusBarStyle { 
    return UIStatusBarStyle.LightContent 
} 


func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell { 

    let cell: PhotoCell = self.collectionView.dequeueReusableCellWithReuseIdentifier("photoCell", forIndexPath: indexPath) as PhotoCell 
    cell.photoImageView.alpha = 0 
    let queue:dispatch_queue_t = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0) 

    dispatch_async(queue, { 
     let searchURL: String = self.flickResults.objectAtIndex(indexPath.item) as String 
     let title: String = self.titleResults.objectAtIndex(indexPath.item) as String 
     let image: UIImage = self.loadImage(searchURL) 
     dispatch_async(dispatch_get_main_queue(), { 
      UIView.animateWithDuration(0.5, animations: { 
       cell.photoImageView.image = image 
       cell.photoTitle.text = title.capitalizedString 
       cell.photoImageView.alpha = 1 
      }) 

     }) 
    }) 

    insertBlurView(cell.titleMask, UIBlurEffectStyle.Dark) 

    return cell 
} 

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { 
    return self.flickResults.count 
} 

func loadImage(imageUrl: String) -> UIImage{ 
    let url = NSURL(string: imageUrl) 
    let data = NSData(contentsOfURL: url!) 
    let image = UIImage(data: data!) 
    return image! 
} 


@IBAction func searchButtonPressed(sender: UIButton) { 
    let storyboard = UIStoryboard(name: "Main", bundle: nil); 
    let vc: SearchViewController = storyboard.instantiateViewControllerWithIdentifier("Search") as SearchViewController 
    providesPresentationContextTransitionStyle = true 
    definesPresentationContext = true 
    vc.modalPresentationStyle = UIModalPresentationStyle.OverCurrentContext 
    self.presentViewController(vc, animated: false, completion: nil) 

} 
} 

VC2

import UIKit 


class SearchViewController: UIViewController, UITextFieldDelegate, UISearchBarDelegate, UICollectionViewDelegate { 


@IBOutlet var searchMask: UIView! 
@IBOutlet var searchField: UITextField! 
@IBOutlet var searchBar: UISearchBar! 

override func viewDidLoad() { 
    super.viewDidLoad() 
    insertBlurView(self.searchMask, UIBlurEffectStyle.Dark) 
} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
} 

@IBAction func exitTap(sender: UIButton) { 
    self.dismissViewControllerAnimated(true, completion: nil) 
} 


func searchBarSearchButtonClicked(searchBar: UISearchBar) { 
    self.dismissViewControllerAnimated(true, completion: { 
     let mainvc = self.storyboard?.instantiateViewControllerWithIdentifier("Main") as MainViewController 
     mainvc.loadPhotos(searchBar.text) 
    }) 
    } 
} 

Answer 1

Благодаря rdelmar, я был в состоянии понять это . с использованием протоколов

Вот что я добавил:

• SearchDelegate
• функция SearchDelegate runSearch()

VC1

class MainViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, SearchDelegate { 

func runSearch(searchString: String) { 
    loadPhotos(searchString) 
} 

} 

VC2

protocol SearchDelegate { 
    func runSearch(searchString: String) 
} 

class SearchViewController: UIViewController, UITextFieldDelegate, UISearchBarDelegate, UICollectionViewDelegate { 


@IBOutlet var searchMask: UIView! 
@IBOutlet var searchField: UITextField! 
@IBOutlet var searchBar: UISearchBar! 

var delegate: SearchDelegate? 

func searchBarSearchButtonClicked(searchBar: UISearchBar) { 
    delegate?.runSearch(searchBar.text) 
    self.dismissViewControllerAnimated(true, completion:nil) 

}