什么会导致这种行为？我有一个带有两个单元格的 Collection View 。两个单元格应具有相同的 View 但不同的文本内容。第二个单元格中什么也没有显示。我在“cellforrowat”中做错了什么吗？我错过了什么？
class UpgradeController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDelegate, UICollectionViewDataSource,UIScrollViewDelegate{
let numMonths = ["1","6","12"]
let months = ["month","months","months"]
let prices = ["$19.99","$79.99","$99.99"]
let pricePerMonth = ["","($13.33 per month)","($8.33 per month)"]
let pricesExtra = ["$29.99","119.99","149.99"]
let pricePerMonthExtra = ["","$19.99 per month","$12.49 per month"]
var collectionView:UICollectionView!
var scrollView:UIScrollView!
let cellId = "cellId"
let cellId2 = "cellId2"
override func viewDidLoad() {
super.viewDidLoad()
self.setupViews()
}
func setupViews(){
let statusBarHeight: CGFloat = UIApplication.shared.statusBarFrame.size.height
let navBarHeight: CGFloat = self.navigationController!.navigationBar.frame.height
let tabBarheight: CGFloat = self.tabBarController!.tabBar.frame.height
let displayWidth: CGFloat = self.view.frame.width
let displayHeight: CGFloat = self.view.frame.height
//view.setGradientBackgroundColor(colorOne: UIColor(rgb:0x000000), colorTwo: UIColor(rgb:0x056644))
navigationController?.navigationBar.isTranslucent = false
setupCollectionView()
setupMenuBar()
scrollView = UIScrollView()
scrollView.backgroundColor = .clear //.orange
scrollView.delegate = self
scrollView.frame = CGRect(x:0,y:50,width:UIScreen.main.bounds.width,height:UIScreen.main.bounds.height)
if let flowLayout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout{
flowLayout.scrollDirection = .horizontal //= .horizontal
}
scrollView.addSubview(self.collectionView)
self.view.addSubview(scrollView)
}
Collection View 设置:
func setupCollectionView(){
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 120, right: 0)
//layout.itemSize = CGSize(width: screenWidth / 3, height: screenWidth / 3)
//layout.itemSize = CGSize(width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.width)
layout.minimumInteritemSpacing = 0
layout.minimumLineSpacing = 0
collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
collectionView.collectionViewLayout = layout
collectionView.dataSource = self
collectionView.delegate = self
collectionView?.register(DragonCell.self, forCellWithReuseIdentifier: cellId)
collectionView!.backgroundColor = UIColor.clear
collectionView.contentInset = UIEdgeInsets(top: 0,left: 0,bottom: 0,right: 0)
collectionView.isPagingEnabled = true
self.view.addSubview(collectionView)
}
let titles = ["Dragon", "DragonExtra"]
lazy var menuBar: MenuBar = {
let mb = MenuBar()
mb.backgroundColor = .red
mb.translatesAutoresizingMaskIntoConstraints = false
mb.names = ["Dragon", "DragonExtra"]
mb.upgradeController = self
return mb
}()
private func setupMenuBar(){
menuBar.setupHorizontalBar()
//menuBar.multiplier = CGFloat(1/8.0)
view.addSubview(menuBar) //view.addSubview(menuBar)
view.addConstraintsWithFormat("H:[v0(\(view.frame.width*CGFloat(menuBar.names.count)/4.0))]", views: menuBar)
view.addConstraintsWithFormat("V:|[v0(50)]|", views: menuBar)
view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:[v1]-(<=1)-[v0]", options: NSLayoutConstraint.FormatOptions.alignAllCenterX, metrics: nil, views: ["v0":menuBar,"v1":self.view])) //center horizontally
}
func scrollToMenuIndex(menuIndex:Int){
let indexPath = NSIndexPath(item: menuIndex, section: 0)
collectionView.scrollToItem(at: indexPath as IndexPath, at: [], animated: true)
//setTitleForIndex(index:menuIndex)
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
//menuBar.horizontalBarLeftAnchorConstraint?.constant = scrollView.contentOffset.x/2 + view.frame.width/8.0
menuBar.horizontalBarLeftAnchorConstraint?.constant = scrollView.contentOffset.x/CGFloat(titles.count*2)
}
func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
let index = targetContentOffset.pointee.x / view.frame.width
let indexPath = NSIndexPath(item: Int(index), section: 0)
menuBar.collectionView.selectItem(at: indexPath as IndexPath, animated: true, scrollPosition: [])
//setTitleForIndex(index:Int(index))
}
private func setTitleForIndex(index:Int){
/*
if let titleLabel = navigationItem.titleView as? UILabel{
titleLabel.text = titles[Int(index)]
}
*/
}
Collection View 委托(delegate)方法:
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 2
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
print(indexPath.item)
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! DragonCell
switch indexPath.item{
case 0:
cell.numMonths = numMonths
cell.months = months
cell.prices = prices
cell.pricePerMonth = pricePerMonth
cell.backgroundColor = .blue
return cell
case 1:
cell.numMonths = numMonths
cell.months = months
cell.prices = pricesExtra
cell.pricePerMonth = pricePerMonthExtra
cell.backgroundColor = .red
return cell
default:
let cell = UICollectionViewCell() //collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
return cell
}
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width:view.frame.width,height:view.frame.height)
}
}
最佳答案
从我在您的代码中看到的内容来看，您想要重用相同的 Collection View 但只是更改内容？
那么为什么不根据选择的菜单栏项目设置一个条件呢？
像这样...
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
print(indexPath.item)
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! DragonCell
//Not exactly sure if this is correct for what you have written
//for your code. But the idea is take the index that is shown or active //from your menu bar.
//You have used a switch statement which used the collection view //index. not the menubar index
if menuBar.index == 0 {
cell.numMonths = numMonths
cell.months = months
cell.prices = prices
cell.pricePerMonth = pricePerMonth
cell.backgroundColor = .blue
return cell
} else {
cell.numMonths = numMonths
cell.months = months
cell.prices = pricesExtra
cell.pricePerMonth = pricePerMonthExtra
cell.backgroundColor = .red
return cell
}
//switch indexPath.item{
//case 0:
//cell.numMonths = numMonths
//cell.months = months
//cell.prices = prices
//cell.pricePerMonth = pricePerMonth
//cell.backgroundColor = .blue
//return cell
//case 1:
//cell.numMonths = numMonths
//cell.months = months
//cell.prices = pricesExtra
//cell.pricePerMonth = pricePerMonthExtra
//cell.backgroundColor = .red
//return cell
//default:
//let cell = UICollectionViewCell() //collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
return cell
}
}
看起来您在 switch 语句中正在使用 Collectionview 的索引路径。但是您不想根据所选菜单栏的索引路径显示内容吗？
但是，我会采用完全不同的方法并为其他 View 创建第二个 Collection View 。
关于ios - UICollectionView 两个具有相同 View 的单元格。第二个单元格什么也没显示，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59564966/