这让我陷入了疯狂。我已经思考这个问题很长一段时间了，尝试了所有的技巧，但没有运气。
如果您能解决我的问题，我将不胜感激。
我的问题是，当我将 Product ViewController 分为几个部分时：-
i) 单元格（即图像）的顺序不正确。
ii) 添加到购物车按钮无法正常工作。
注意： - 如果以下代码对您来说似乎很广泛，请保留其余代码，只需查看 ProductViewController - 我只想能够按照我的意愿将 ProductViewController 划分为多个部分，并且“添加到购物车”按钮正常工作，很可能无需更改模型。我放置了冗长的代码以防万一，也为了展示我已经尝试过的内容（在其他人的帮助下）。
如果你时间很紧，我也在这里问了这个问题的不全面或较小的版本 -带部分的 UITableView 在所有部分中重复单元格数据 https://stackoverflow.com/q/63918495/7444874，但我仍然要求您阅读下面的完整代码 -
稍后我将阐明这两点。首先请看我的代码 -
Models -
结构产品 -
import UIKit
struct Product:Equatable {
let name : String
var quantity : Int
var price : Double
let imagename: UIImage
// var subTotal : Double {
//return Double(quantity) * price }
}
var productarray = [Product(name: "a", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "blue")),
Product(name: "b", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "CakeImage")),Product(name: "c", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "vectorlogo")),
Product(name: "d", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "PeasImge")),Product(name: "e", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "castle")),
Product(name: "f", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "scoobydoo")),Product(name: "g", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "ufo")),
Product(name: "h", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "wolfsky")),Product(name: "i", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "universe")),
Product(name: "j", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "werewolf")),Product(name: "k", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "galaxy"))]
购物车项目类 -
import Foundation
class CartItem {
var quantity : Int = 1
var product : Product
// var subTotal : Float { get { return Float(product.price) * Float(quantity) } }
init(product: Product) {
self.product = product
}
}
类购物车 -
import Foundation
class Cart {
var items : [CartItem] = []
}
extension Cart {
/* var total: Float {
get { return items.reduce(0.0) { value, item in
value + item.subTotal
}
}
}*/
var totalQuantity : Int {
get { return items.reduce(0) { value, item in
value + item.quantity
}
}
}
func updateCart(with product: Product) {
if !self.contains(product: product) {
self.add(product: product)
} else {
self.remove(product: product)
}
}
func updateCart() {
for item in self.items {
if item.quantity == 0 {
updateCart(with: item.product)
}
}
}
func add(product: Product) {
let item = items.filter { $0.product == product }
if item.first != nil {
item.first!.quantity += 1
} else {
items.append(CartItem(product: product))
}
}
func remove(product: Product) {
guard let index = items.firstIndex(where: { $0.product == product }) else { return}
items.remove(at: index)
}
func contains(product: Product) -> Bool {
let item = items.filter { $0.product == product }
return item.first != nil
}
}
产品视图控制器类 -
import UIKit
class ProductViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
let sections = ["Section A", "Section B","Section C", "Section D","Section E"]
let rowspersection = [2,3,2,2,2]
fileprivate var cart = Cart()
@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self }
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
//Workaround to avoid the fadout the right bar button item
self.navigationItem.rightBarButtonItem?.isEnabled = false
self.navigationItem.rightBarButtonItem?.isEnabled = true
//Update cart if some items quantity is equal to 0 and reload the product table and right button bar item
cart.updateCart()
self.navigationItem.rightBarButtonItem?.title = "Checkout (\(cart.items.count))"
tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showCart" {
if let cartViewController = segue.destination as? CartViewController {
cartViewController.cart = self.cart
}
}
}
func numberOfSections(in tableView: UITableView) -> Int {
return sections.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return rowspersection[section]
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ProductTableViewCell") as! ProductTableViewCell
cell.delegate = self
var index = indexPath.row
if indexPath.section != 0, rowspersection.count > indexPath.section - 1{
index += rowspersection[indexPath.section - 1]
}
if index < productarray.count {
let data = productarray[index]
cell.name?.text = data.name
cell.imageView?.image = data.imagename
let product = productarray[index]
cell.setButton(state: self.cart.contains(product: product))
}
return cell
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 44
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
switch(section) {
case 0:return "Section A"
case 1:return "Section B"
case 2:return "Section C"
case 3:return "Section D"
case 4:return "Section E"
default :return ""
}
}
}
extension ProductViewController: CartDelegate {
// MARK: - CartDelegate
func updateCart(cell: ProductTableViewCell) {
guard let indexPath = tableView.indexPath(for: cell) else { return }
var index = indexPath.row
if indexPath.section != 0, rowspersection.count > indexPath.section - 1{
index += rowspersection[indexPath.section - 1]
}
if index < productarray.count{
let product = productarray[index]
//Update Cart with product
cart.updateCart(with: product)
self.navigationItem.rightBarButtonItem?.title = "Checkout (\(cart.items.count))"
}
}
}
产品 TableViewCell 类 -
import UIKit
protocol CartDelegate {
func updateCart(cell: ProductTableViewCell) }
class ProductTableViewCell: UITableViewCell {
weak var myParent:ProductViewController?
@IBOutlet weak var name: UILabel!
@IBOutlet weak var price: UILabel!
@IBOutlet weak var imagename: UIImageView!
@IBOutlet weak var addToCartButton: UIButton!
var delegate: CartDelegate?
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
addToCartButton.layer.cornerRadius = 5
addToCartButton.clipsToBounds = true
}
func setButton(state: Bool) {
addToCartButton.isSelected = state
addToCartButton.backgroundColor = (!addToCartButton.isSelected) ? .black : .red
}
@IBAction func addToCart(_ sender: Any) {
setButton(state: !addToCartButton.isSelected)
self.delegate?.updateCart(cell: self)
}
}
类 CartViewController -
import UIKit
class CartViewController: UIViewController {
@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var totalView: UIView!
@IBOutlet weak var totalLabel: UILabel!
var cart: Cart? = nil
fileprivate let reuseIdentifier = "CartItemCell"
override func viewDidLoad() {
super.viewDidLoad()
tableView.tableFooterView = UIView(frame: .zero)
}
}
extension CartViewController: UITableViewDelegate, UITableViewDataSource {
// MARK: - Table view data source
func numberOfSections(in tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return (cart?.items.count)!
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: reuseIdentifier, for: indexPath) as! CartItemTableViewCell
if let cartItem = cart?.items[indexPath.item] {
cell.delegate = self as CartItemDelegate
// cell.nameLabel.text = cartItem.productarray.name
// cell.priceLabel.text = cartItem.product.displayPrice()
// cell.quantityLabel.text = String(describing: cartItem.quantity)
cell.quantity = cartItem.quantity
}
return cell
}
}
extension CartViewController: CartItemDelegate {
// MARK: - CartItemDelegate
func updateCartItem(cell: CartItemTableViewCell, quantity: Int) {
guard let indexPath = tableView.indexPath(for: cell) else { return }
guard let cartItem = cart?.items[indexPath.row] else { return }
//Update cart item quantity
cartItem.quantity = quantity
}
}
类 CartItem TableViewCell -
import UIKit
protocol CartItemDelegate {
func updateCartItem(cell: CartItemTableViewCell, quantity: Int) }
class CartItemTableViewCell: UITableViewCell {
@IBOutlet weak var nameLabel: UILabel!
@IBOutlet weak var priceLabel: UILabel!
@IBOutlet weak var incrementButton: UIButton!
@IBOutlet weak var decrementButton: UIButton!
@IBOutlet weak var quantityLabel: UILabel!
var delegate: CartItemDelegate?
var quantity: Int = 1
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
incrementButton.layer.cornerRadius = 10
incrementButton.clipsToBounds = true
decrementButton.layer.cornerRadius = 10
decrementButton.clipsToBounds = true
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
@IBAction func updateCartItemQuantity(_ sender: Any) {
if (sender as! UIButton).tag == 0 {
quantity = quantity + 1
} else if quantity > 0 {
quantity = quantity - 1
}
decrementButton.isEnabled = quantity > 0
decrementButton.backgroundColor = !decrementButton.isEnabled ? .gray : .black
self.quantityLabel.text = String(describing: quantity)
self.delegate?.updateCartItem(cell: self, quantity: quantity)
}
}
结果是这样的。请先看图片，然后我会解释什么是错误的
1）模型“结构产品”中的图像/单元按顺序排列 - 蓝色、CakeImage、vectorlogo、PeasImage、城堡、scoobydoo、ufo、wolfsky、宇宙、狼人、星系
但模拟器中的图像（见上图）的模式不稳定 -
A 部分：蓝色，蛋糕图像，矢量标志
B 部分：矢量标志、PeasImge、城堡。
C 部分：豌豆图像，城堡。
D 部分：豌豆图像，城堡。
E 部分：豌豆图像，城堡。
- 只是图像并不不稳定，单元格上的“添加”按钮也不稳定 - 单击下部部分中的“添加”按钮
有时增加和减少 rightBarButtonItem 即 Chekcout(4)
我之前曾问过一个类似版本的问题，用户 PGDev 建议 -
不是创建不同的数组，而是创建自定义类型的单个数组并将其用作 tableView 的数据源。例子：
struct Section {
let name: String
let products: [Product]
}
let sections = [
Section(name: "Section A", products: [Product(name: "a", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "blue")),
Product(name: "b", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "CakeImage"))]),
Section(name: "Section B", products: [Product(name: "c", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "vectorlogo")),
Product(name: "d", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "PeasImge")),Product(name: "e", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "castle"))]),
Section(name: "Section C", products: [Product(name: "f", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "scoobydoo")),Product(name: "g", quantity: 5, price: 5.0,imagename:#imageLiteral(resourceName: "ufo"))]),
Section(name: "Section D", products: [Product(name: "h", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "wolfsky")),Product(name: "i", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "universe"))]),
Section(name: "Section E”, products: [ Product(name: "j", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "werewolf")),Product(name: "k", quantity: 10, price: 10.0, imagename:#imageLiteral(resourceName: "galaxy"))]])
]
即使用sections数组作为数据源以避免很多混乱。
我也准备这样做，也许这种方法更好，但随后我将不得不更改代码的许多部分。该怎么做呢？
我只想实现以下目标——
-
按照我的意愿将 ProdutViewcontroller 的单元格/图像分成几个部分。
-
将数据添加到 rightBarButtonItem，即正确结帐，随后应将其传输到 CartViewController。
.. 别着急。花你自己的时间来解决问题，但对我来说修复它们至关重要，因为我需要为生产应用程序提供类似的代码。我陷入了两难的境地。请保释我。我将非常感激。
