インターネットから収集した画像を収集する

Question

こんにちは、私は作成しようとして学んでいます。私は作業中のデモコードを持っていて、表示されている画像（ハードの名前）（車の名前）を変更し、代わりにURLから画像を表示するように変更する方法があるかどうかを知りたがっています。私はこのことを勉強しているし、他のもののためにそれをする方法の例を得ることができますが、このコードにそれを得るのに苦労しているようです。私はあなたが助けることを願っています

私はクラスコールポストを持っており、私はfirebaseから画像を取得しています。だから私は使用：画像のURLのpost.imageUrl1。

class DemoViewController: ExpandingViewController { 
@IBAction func backPressed(_ sender: Any) { 
} 

    var post: Post! 

typealias ItemInfo = (imageName: String, title: String) 
fileprivate var cellsIsOpen = [Bool]() 
fileprivate let items: [ItemInfo] = [("Ferrari", "Ferrari"),("Bug", "Bugatti"),("car", "Mustang"),("BM", "BMW")] 

@IBOutlet weak var pageLabel: UILabel! 
@IBOutlet weak var titleImageView: UIImageView! 
@IBOutlet weak var titleImageViewXConstraint: NSLayoutConstraint! 

} 

// MARK: - Lifecycle 
extension DemoViewController { 



override func viewDidLoad() { 
itemSize = CGSize(width: 256, height: 335) 
super.viewDidLoad() 




registerCell() 
fillCellIsOpenArray() 
addGesture(to: collectionView!) 
configureNavBar() 
} 

override func viewWillLayoutSubviews() { 
super.viewWillLayoutSubviews() 
guard let titleView = navigationItem.titleView else { return } 
let center = UIScreen.main.bounds.midX 
let diff = center - titleView.frame.midX 
titleImageViewXConstraint.constant = diff 
} 


} 

// MARK: Helpers 
extension DemoViewController { 

fileprivate func registerCell() { 

    let nib = UINib(nibName: String(describing:  DemoCollectionViewCell.self), bundle: nil) 
collectionView?.register(nib, forCellWithReuseIdentifier: String(describing: DemoCollectionViewCell.self)) 
    } 

    fileprivate func fillCellIsOpenArray() { 
    cellsIsOpen = Array(repeating: false, count: items.count) 
    } 

fileprivate func getViewController() -> ExpandingTableViewController { 
let storyboard = UIStoryboard(storyboard: .Main) 
let toViewController: DemoTableViewController = storyboard.instantiateViewController() 
return toViewController 
} 

fileprivate func configureNavBar() { 
navigationItem.leftBarButtonItem?.image = navigationItem.leftBarButtonItem?.image!.withRenderingMode(UIImageRenderingMode.alwaysOriginal) 
} 

} 

/// MARK: Gesture 
extension DemoViewController { 

fileprivate func addGesture(to view: UIView) { 
let upGesture = Init(UISwipeGestureRecognizer(target: self, action: #selector(DemoViewController.swipeHandler(_:)))) { 
    $0.direction = .up 
} 

let downGesture = Init(UISwipeGestureRecognizer(target: self, action: #selector(DemoViewController.swipeHandler(_:)))) { 
    $0.direction = .down 
} 
view.addGestureRecognizer(upGesture) 
view.addGestureRecognizer(downGesture) 
} 

func swipeHandler(_ sender: UISwipeGestureRecognizer) { 
let indexPath = IndexPath(row: currentIndex, section: 0) 
guard let cell = collectionView?.cellForItem(at: indexPath) as? DemoCollectionViewCell else { return } 
// double swipe Up transition 
if cell.isOpened == true && sender.direction == .up { 
    pushToViewController(getViewController()) 

    if let rightButton = navigationItem.rightBarButtonItem as? AnimatingBarButton { 
    rightButton.animationSelected(true) 
    } 
    } 

    let open = sender.direction == .up ? true : false 
    cell.cellIsOpen(open) 
    cellsIsOpen[indexPath.row] = cell.isOpened 
    } 

    } 

// MARK: UIScrollViewDelegate 
extension DemoViewController { 

func scrollViewDidScroll(_ scrollView: UIScrollView) { 
pageLabel.text = "\(currentIndex+1)/\(items.count)" 
} 

} 

// MARK: UICollectionViewDataSource 
extension DemoViewController { 



override func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) { 
super.collectionView(collectionView, willDisplay: cell, forItemAt: indexPath) 
guard let cell = cell as? DemoCollectionViewCell else { return } 

let index = indexPath.row % items.count 
let info = items[index] 
cell.backgroundImageView?.image = UIImage(named: info.imageName) 
cell.customTitle.text = info.title 
cell.cellIsOpen(cellsIsOpen[index], animated: false) 
} 

func collectionView(_ collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: IndexPath) { 
guard let cell = collectionView.cellForItem(at: indexPath) as? DemoCollectionViewCell 
     , currentIndex == indexPath.row else { return } 

if cell.isOpened == false { 
    cell.cellIsOpen(true) 
} else { 
    pushToViewController(getViewController()) 

    if let rightButton = navigationItem.rightBarButtonItem as? AnimatingBarButton { 
    rightButton.animationSelected(true) 
    } 
    } 
} 

} 

// MARK: UICollectionViewDataSource 
extension DemoViewController { 

override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { 
return items.count 
} 

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { 
return collectionView.dequeueReusableCell(withReuseIdentifier: String(describing: DemoCollectionViewCell.self), for: indexPath) 

    } 

} 

Answer 1

あなたは、データの指定されたコンストラクタを使用してURLから画像をダウンロードすることができます：let imageData = Data(contentsOf: "exampleURL.com")

その後、あなたは自分のコレクションビューデータソース方式でこれを使用します。swift2ため

override func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) { 
    super.collectionView(collectionView, willDisplay: cell, forItemAt: indexPath) 
    guard let cell = cell as? DemoCollectionViewCell else { return } 

    let index = indexPath.row % items.count 
    let info = items[index] 
    //here I assumed you would create a .url property of ItemInfo, but you can access the URL any way you want to 
    guard let imageUrl = URL(string: info.url) else { return } 
    do { 
     let imageData = try Data(contentsOf: imageUrl) 
    } catch { 
     //handle error here 
    } 
    cell.backgroundImageView?.image = UIImage(data: imageData) 
    cell.customTitle.text = info.title 
    cell.cellIsOpen(cellsIsOpen[index], animated: false) 
}