下面是CatalogViewController，它保存一个表视图。该表视图有一个原型单元格ShopCell。当我打印循环中的项目时，它们打印正确，但当显示在表中时，项目会丢失。(删除shuffle((方法没有任何作用&删除removeDuplicates((，项目会出现多次(。我没有包括addToFavorites(cell:ShopCell(，因为我正在测试它。它什么都不做。
protocol ShopCellDelegate {
func addToFavorites(cell: ShopCell)
}
class ShopCell: UITableViewCell {
@IBOutlet weak var productImageView: UIImageView!
@IBOutlet weak var titleLabel: UILabel!
@IBOutlet weak var priceLabel: UILabel!
@IBOutlet weak var descTV: UITextView!
@IBOutlet weak var favoriteButton: UIButton!
var delegate: ShopCellDelegate?
override func prepareForReuse() {
super.prepareForReuse()
self.productImageView.image = nil
self.titleLabel.text = ""
self.priceLabel.text = ""
self.descTV.text = ""
self.favoriteButton.isHidden = true
}
func setProduct(product: Product) {
productImageView.sd_setImage(with: URL(string: product.urlToImage!), placeholderImage: UIImage(named: "1024ELP.png"))
titleLabel.text = product.itemName!
priceLabel.text = product.priceTag!
descTV.text = product.itemDesc!
}
@IBAction func favOrUnfav(_ sender: UIButton) {
if let delegate = self.delegate {
delegate.addToFavorites(cell: self)
}
}
}
//
class CatelogViewController: UIViewController, GADInterstitialDelegate, SFSafariViewControllerDelegate, UITableViewDelegate, UITableViewDataSource, ShopCellDelegate {
@IBOutlet weak var tableView: UITableView!
static var shopType = String()
static var linkToVisit = String()
var myProducts = [Product]()
var productKeys = [String]()
var interstitial: GADInterstitial!
override func viewWillAppear(_ animated: Bool) {
visuals() // Sets Nav Bar color & changes cell size if device == ipad
}
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.delegate = self
self.tableView.dataSource = self
self.navigationController?.navigationBar.tintColor = UIColor.black
if CatelogViewController.shopType == "Apparel" {
self.title = NSLocalizedString("Shop Apparel", comment: "")
fetchProductLinks(child1: "ProductList", child2: "Products")
}else{
self.title = NSLocalizedString("Shop Others", comment: "")
fetchProductLinks(child1: "OtherList", child2: "OtherProducts")
//shuffleItems()
}
if let index = self.tableView.indexPathForSelectedRow{
self.tableView.deselectRow(at: index, animated: true)
}
}
// MARK: - Table view data source
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return myProducts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! ShopCell
let product = myProducts[indexPath.row]
cell.delegate = self
cell.favoriteButton.isHidden = true
cell.setProduct(product: product)
return cell
}
func fetchProductLinks(child1: String, child2: String) {
let ref = Database.database().reference()
let prodRef = ref.child(child1).child(child2)
prodRef.observeSingleEvent(of: .value, with: { snapshot in
self.myProducts.removeAll()
for items in snapshot.children {
let item = items as! DataSnapshot
let product = item.value as! [String : String]
let name = product["Name"]
let link = product["Link"]
let img = product["urlToImage"]
let desc = product["Description"]
let price = product["Price"]
let newProduct = Product(urlToImage: img, itemName: name, itemLink: link, itemDesc: desc, priceTag: price)
self.myProducts.append(newProduct)
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
self.myProducts = self.shuffleArray(array: self.myProducts) as! [Product]
self.myProducts = self.myProducts.removeDuplicates()
})
ref.removeAllObservers()
}
extension Array where Element:Equatable {
func removeDuplicates() -> [Element] {
var result = [Element]()
for value in self {
if result.contains(value) == false {
result.append(value)
}
}
return result
}
}
您打乱数组并删除重复项，但之后不会重新加载数据。因此，重新加载表视图的数据
self.myProducts = self.shuffleArray(array: self.myProducts) as! [Product]
self.myProducts = self.myProducts.removeDuplicates()
self.tableView.reloadData()