使用Swift 5.1.3,iOS13.3,XCode11.3,
我尝试显示水平的collectionView,其宽度大于视图的宽度。通过拖动,collectionView单元格将水平滚动。
现在的问题如下:一旦我单击拖动,collectionView内容就会“消失”(即变为透明)。如果仔细看,您会发现滚动条仍然存在。
为什么collectionView内容一点击就变成透明的?
这里是说明错误行为的视频:
下面将找到相应的代码:
这里是代码:
在我的Main-ViewController内部,添加collectionView:
override func viewDidLoad() {
super.viewDidLoad()
let cardsHorizontalController = CardsHorizontalController()
self.view.addSubview(cardsHorizontalController.view)
cardsHorizontalController.view.translatesAutoresizingMaskIntoConstraints = false
cardsHorizontalController.view.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 100.0).isActive = true
cardsHorizontalController.view.heightAnchor.constraint(equalToConstant: 279).isActive = true
cardsHorizontalController.view.widthAnchor.constraint(equalToConstant: UIScreen.main.bounds.width).isActive = true
}
这是collectionView控制器类:
class CardsHorizontalController: BaseListController, UICollectionViewDelegateFlowLayout {
let cellId = "cellId"
override func viewDidLoad() {
super.viewDidLoad()
collectionView.backgroundColor = .clear
collectionView.register(CardHeaderCell.self, forCellWithReuseIdentifier: cellId)
if let layout = collectionViewLayout as? UICollectionViewFlowLayout {
layout.scrollDirection = .horizontal
}
collectionView.contentInset = UIEdgeInsets(top: 100, left: 0, bottom: 0, right: 0)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return .init(width: view.frame.width - 48, height: view.frame.height)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return .init(top: 0, left: 16, bottom: 0, right: 0)
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
return cell
}
}
及其对应的父类:
class BaseListController: UICollectionViewController {
init() {
super.init(collectionViewLayout: UICollectionViewFlowLayout())
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
这里是正在播放的collectionView单元:
class CardHeaderCell: UICollectionViewCell {
let imageView = UIImageView(cornerRadius: 8)
override init(frame: CGRect) {
super.init(frame: frame)
imageView.backgroundColor = .red
let stackView = VerticalStackView(arrangedSubviews: [
// companyLabel,
// titleLabel,
imageView
], spacing: 12)
addSubview(stackView)
stackView.fillSuperview(padding: .init(top: 16, left: 0, bottom: 0, right: 0))
}
required init?(coder aDecoder: NSCoder) {
fatalError()
}
}
我终于找到了解决方案:
需要将collectionView-Controller(即CardsHorizontalController()
)添加为ChildController!
在Main-ViewController的viewDidLoad()
内部(在上面的代码的第一段中,请替换下面的行...
self.view.addSubview(cardsHorizontalController.view)
带有以下内容:
self.addChild(cardsHorizontalController)
self.view.addSubview(cardsHorizontalController.view)
self.didMove(toParent: cardsHorizontalController)
已经这样做,一切都按预期工作!
您在此GitHub存储库中找到一个正在运行的项目(仅使用CollectionView进行了精简):https://github.com/iKK001/HorizontalCollectionViewExample
由于我很高兴-这是一个水平卧式CollectionView的视频:
您是否尝试过将return .init(width: view.frame.width - 48, height: view.frame.height)
中的sizeForItemAt
更改为return .init(width: collectionView.frame.width - 48, height: collectionView.frame.height)
?