不确定我到底在做什么错。我列出了我的问题和代码。希望得到一些帮助。
谢谢！
问题：
VC1代表VC2。
VC1中的IBOutlet现在为零。
VC2退回到VC1。
VC1中的IBOutlets仍然为零。
VC1从flickR加载图片网格。 VC2具有searchBar控制器，当VC2关闭时，它会运行flickR查询。就在我self.collectionView.reload（）失败之前，因为self.collectionView为nil :(
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)
})
}
}
最佳答案
多亏了rdelmar，我才能够使用协议解决这个问题。
这是我添加的内容：
SearchDelegate
SearchDelegate函数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)
}
关于ios - IBOutlet在实例化ViewControllerWithIdentifier后为nil，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/28732084/