投射细胞类型出列的问题
您好，我在我的cellForItemAt它说下面的错误有问题。 我不明白为什么我无法投出细胞。 它发生在else语句的第一行。
列出的UIView上的UIConstraintBasedLayoutDebugging类中的方法也可能有所帮助。
无法将类型'Spoexs.MenuCell2'（0x10d059660）的值转换为'Spoexs.MenuCell1'（0x10d0595c0）。
import UIKit
import MIBadgeButton_Swift
class SecondMenuBar: UIView, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = UIColor.rgb(r:240, g:240, b:240)
cv.dataSource = self
cv.delegate = self
return cv
}()
let cellId = "cellId"
let cellId2 = "cellId2"
let menuItems = ["inventory", "checkout", "scanner"]
var inventoryController: InventoryTabController?
override init(frame: CGRect){ //on run
super.init(frame: frame)
collectionView.register(MenuCell1.self,
forCellWithReuseIdentifier: cellId) //registering superclass
collectionView.register(MenuCell2.self,
forCellWithReuseIdentifier: cellId) //registering superclass
addSubview(collectionView)
addConstraintsWithFormat("H:|[v0]|", views: collectionView)
addConstraintsWithFormat("V:|[v0]|", views: collectionView)
let selectedIndexPath = NSIndexPath(item:0, section:0)
collectionView.selectItem(at: selectedIndexPath as IndexPath, animated: false, scrollPosition: []) //home button glows on run
//setup horizontal bar
slider()
NotificationCenter.default.addObserver(forName: .arrayValueChanged, object: nil, queue: OperationQueue.main) { [weak self] (notif) in
badge = "(checkout.count)"
self?.collectionView.reloadData()
}
}
deinit {
NotificationCenter.default.removeObserver(self)
}
var horizontalBarLeftAnchorConstraint: NSLayoutConstraint?
func slider() {
let horizontalBarView = UIView()
if #available(iOS 10.0, *) {
horizontalBarView.backgroundColor = UIColor(displayP3Red:0.29, green:0.78, blue:0.47, alpha:0.2)
} else {
horizontalBarView.backgroundColor = UIColor.rgb(r:190, g:190, b:190)
}
horizontalBarView.translatesAutoresizingMaskIntoConstraints = false
addSubview(horizontalBarView) //add to hierarchy
// need x,y coordinate
horizontalBarLeftAnchorConstraint = horizontalBarView.leftAnchor.constraint(equalTo: self.leftAnchor)
horizontalBarLeftAnchorConstraint?.isActive = true
horizontalBarView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
horizontalBarView.widthAnchor.constraint(equalTo: self.widthAnchor, multiplier: 1/3).isActive = true
horizontalBarView.heightAnchor.constraint(equalToConstant: 3).isActive = true
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
inventoryController?.scrollToMenuIndex(menuIndex: indexPath.item)
print("Right here (indexPath.section)")
print("Right here (indexPath.item)")
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: frame.width/3, height: frame.height)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView,
numberOfItemsInSection section: Int) -> Int {
return 3
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if indexPath.section == 1{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId2, for: indexPath) as! MenuCell2
cell.imageView2.setImage(UIImage(named:menuItems[indexPath.section])?.withRenderingMode(.alwaysTemplate), for: .normal)
cell.imageView2.badgeString = badge
cell.tintColor = UIColor.rgb(r:255, g:0, b:255) //set tint color
return cell
} else{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! MenuCell1
cell.imageView1.image = UIImage(named: menuItems[indexPath.section])?.withRenderingMode(.alwaysTemplate)
cell.tintColor = UIColor.rgb(r:255, g:0, b:255) //set tint color
return cell
}
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class MenuCell1: UICollectionViewCell {
override init(frame: CGRect){
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let imageView1: UIImageView = {
let iv = UIImageView()
iv.image = UIImage(named: "")?.withRenderingMode(.alwaysTemplate)
iv.tintColor = UIColor.rgb(r:144, g:157, b:255)//set tint color of each menu image bg
return iv
}()
override var isSelected: Bool {
didSet {
imageView1.tintColor = isSelected ? UIColor.rgb(r:76, g:200, b:120) : UIColor.rgb(r:190, g:190, b:190) //green when selected otherwise grey
}
}
func setupViews() {
addSubview(imageView1)
addConstraintsWithFormat("H:[v0(28)]", views: imageView1)
addConstraintsWithFormat("V:[v0(28)]", views: imageView1)
addConstraint(NSLayoutConstraint(item: imageView1, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier:1, constant: 0)) //center menu icons
addConstraint(NSLayoutConstraint(item: imageView1, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier:1, constant: 0))
}
}
class MenuCell2: UICollectionViewCell {
override init(frame: CGRect){
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let imageView2: MIBadgeButton = {
let button = MIBadgeButton()
var image = UIImage(named: "home")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.badgeString = badge
button.isUserInteractionEnabled = false
button.tintColor = UIColor.rgb(r:190, g:190, b:190) //intital button tint grey
return button
}()
override var isSelected: Bool {
didSet {
imageView2.tintColor = isSelected ? UIColor.rgb(r:76, g:200, b:120) : UIColor.rgb(r:190, g:190, b:190) //green when selected otherwise grey
}
}
func setupViews() {
addSubview(imageView2)
addConstraintsWithFormat("H:[v0(28)]", views: imageView2)
addConstraintsWithFormat("V:[v0(28)]", views: imageView2)
addConstraint(NSLayoutConstraint(item: imageView2, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier:1, constant: 0)) //center menu icons
addConstraint(NSLayoutConstraint(item: imageView2, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier:1, constant: 0))
}
}
你注册单元类的代码是错误的：
collectionView.register(MenuCell1.self, forCellWithReuseIdentifier: cellId)
collectionView.register(MenuCell2.self, forCellWithReuseIdentifier: cellId) // <-- probably not intended
您正在为同一个cellId注册两个类，其中一个应该是cellId2 ：
collectionView.register(MenuCell1.self, forCellWithReuseIdentifier: cellId)
collectionView.register(MenuCell2.self, forCellWithReuseIdentifier: cellId2)
问题是这条线：
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! MenuCell1
您为此重用标识符注册的单元格是MenuCell2，所以这就是您所得到的。 你不能神奇地把它变成一个MenuCell1！
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