在我的项目中，用户可以创建一个UIView(“CustomWishlistView”)，如下所示:
func createCustomWishlistView() -> CustomWishlistView {
let v = CustomWishlistView()
v.translatesAutoresizingMaskIntoConstraints = false
v.backgroundColor = .darkGray
v.layer.cornerRadius = 30
return v
}
@IBAction func createListButtonTapped(_ sender: Any) {
// "Liste erstellen" button was tapped
self.appDidEnterBackgroundHandler()
if let txt = listNameTextfield.text {
self.newListTextfield.resignFirstResponder()
// append user-entered text to the data array
self.theData.append(txt)
self.imageData.append(self.image!)
let theCustomWishlistView = createCustomWishlistView()
self.view.addSubview(theCustomWishlistView)
// constrain CustomWishlistView
theCustomWishlistView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 120.0).isActive = true
theCustomWishlistView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
theCustomWishlistView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 30.0).isActive = true
theCustomWishlistView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -30.0).isActive = true
theCustomWishlistView.wishlistImage.image = self.image
theCustomWishlistView.wishlistLabel.text = txt
theCustomWishlistView.transform = CGAffineTransform(translationX: 0, y: 1000)
self.view.bringSubviewToFront(containerView)
// reload the collection view
theCollectionView.reloadData()
theCollectionView.performBatchUpdates(nil, completion: {
(result) in
// scroll to make newly added row visible (if needed)
let i = self.theCollectionView.numberOfItems(inSection: 0) - 1
let idx = IndexPath(item: i, section: 0)
self.theCollectionView.scrollToItem(at: idx, at: .bottom, animated: true)
// close (hide) the "New List" view
self.closeButtonTappedNewList(nil)
})
}
}
我转换该 View ，使其一开始不可见。它应该在用户单击 UICollectionView 内的 cell 后出现。我的代码(在 cellForItemAt 内)如下所示:
if indexPath.item <= theData.count {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ContentCell", for: indexPath) as! ContentCell
cell.testLabel.text = theData[indexPath.item - 1]
cell.buttonView.setImage(imageData[indexPath.item - 1], for: .normal)
cell.customWishlistTapCallback = {
// let CustomWishlistView appear
// UIView.animate(withDuration: 0.3, delay: 0, options: .curveEaseIn, animations: {
// theCustomWishlistView.transform = CGAffineTransform(translationX: 0, y: 0)
// })
// let welcomeText disappear
UIView.animate(withDuration: 0.2, delay: 0, options: .curveEaseOut, animations: {
self.welcomeTextLabel.transform = CGAffineTransform(translationX: 0, y: 0)
})
}
return cell
}
我的问题是我无法让我的 customWishlistView 出现，因为我无法访问它。有办法解决这个问题吗？ :)
最佳答案
您需要使 theCustomWishlistView 成为如下所示的实例变量。你没有显示整个类代码，所以我的解决方案是尽可能完整的，而无需看到你的其余代码
class CustomViewController: UIViewController, UICollectionViewDataSource {
var theCustomWishlistView: UIView?
func createCustomWishlistView() -> CustomWishlistView {
let v = CustomWishlistView()
v.translatesAutoresizingMaskIntoConstraints = false
v.backgroundColor = .darkGray
v.layer.cornerRadius = 30
return v
}
@IBAction func createListButtonTapped(_ sender: Any) {
// "Liste erstellen" button was tapped
self.appDidEnterBackgroundHandler()
if let txt = listNameTextfield.text {
self.newListTextfield.resignFirstResponder()
// append user-entered text to the data array
self.theData.append(txt)
self.imageData.append(self.image!)
let wishlistView = createCustomWishlistView()
self.view.addSubview(wishlistView)
// constrain wishlistView
wishlistView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 120.0).isActive = true
wishlistView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
wishlistView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 30.0).isActive = true
wishlistView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -30.0).isActive = true
wishlistView.wishlistImage.image = self.image
wishlistView.wishlistLabel.text = txt
wishlistView.transform = CGAffineTransform(translationX: 0, y: 1000)
// retain wishlist view in instance variable
self.theCustomWishlistView = wishlistView
self.view.bringSubviewToFront(containerView)
// reload the collection view
theCollectionView.reloadData()
theCollectionView.performBatchUpdates(nil, completion: {
(result) in
// scroll to make newly added row visible (if needed)
guard let i = self.theCollectionView.numberOfItems(inSection: 0) else { return }
let idx = IndexPath(item: i - 1, section: 0)
self.theCollectionView.scrollToItem(at: idx, at: .bottom, animated: true)
// close (hide) the "New List" view
self.closeButtonTappedNewList(nil)
})
}
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return theData.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let _cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ContentCell", for: indexPath)
guard let cell = _cell as? ContentCell else { return _cell }
cell.testLabel.text = theData[indexPath.item - 1]
cell.buttonView.setImage(imageData[indexPath.item - 1], for: .normal)
cell.customWishlistTapCallback = {
// let CustomWishlistView appear
UIView.animate(withDuration: 0.3, delay: 0, options: .curveEaseIn, animations: {
self.theCustomWishlistView?.transform = CGAffineTransform(translationX: 0, y: 0)
})
// let welcomeText disappear
UIView.animate(withDuration: 0.2, delay: 0, options: .curveEaseOut, animations: {
self.welcomeTextLabel.transform = CGAffineTransform(translationX: 0, y: 0)
})
}
return cell
}
}
关于ios - Swift - 从另一个函数访问 UIView 的实例，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59165999/