为什么我的收藏夹视图单元格中的步进值没有变化？

Question

我有集合视图单元格，并且在集合视图单元格中有步进器和产品名称标签。我有六个产品显示在集合视图单元格上。我想通过点击添加到购物车按钮将产品添加到购物车/订单。

点击添加到购物车按钮后，将隐藏添加到购物车按钮，并显示步进器，如下图所示。

这是我的集合视图单元格的代码：

protocol OrderCellDelegate {
   func stepperValueChange(at selectedIndexPath: IndexPath, stepperValue: Int)
}


class OrderCell: UICollectionViewCell {

    @IBOutlet weak var stepper: GMStepper!
    @IBOutlet weak var nameLabel: UILabel!
    @IBOutlet var addToCartButton: UIButton!

    var productData : Product? {
        didSet {
            updateUI()
        }
    }

    var indexPath: IndexPath?
    var delegate: OrderCellDelegate?

    override func awakeFromNib() {
        super.awakeFromNib()

        setStepper()

    }


    @IBAction func addToCartButtonDidTapped(_ sender: Any) {
        stepper.value = 1.0
    }


    @IBAction func stepperValueChanged(_ sender: Any) {

        print("stepper value: \(stepper.value)")

        guard let selectedIndexPath = indexPath else {return}
        let value = Int(stepper.value)
        self.delegate?.stepperValueChange(at: selectedIndexPath, stepperValue: value)
    }




    func setStepper() {
        stepper.autorepeat = false
        stepper.minimumValue = 0
        stepper.maximumValue = 100
        stepper.stepValue = 1.0
    }

    func updateUI() {
        guard let product = productData else {return}
        nameLabel.text = product.name
        setCartAndStepperButton()
    }

    private func setCartAndStepperButton() {

        guard let selectedProduct = productData else {return}
        func showStepperButton(status: Bool) {
            // to decide whether to show stepper or add to cart button.
            stepper.isHidden = !status
            stepper.isEnabled = status

            addToCartButton.isHidden = status
            addToCartButton.isEnabled = !status

        }

        if selectedProduct.quantityInCart == 0 {
            showStepperButton(status: false)
        } else {
            showStepperButton(status: true)
        }


    }


}

正如您在上面的addToCartButtonDidTapped方法中所看到的那样，我以编程方式将步进器值设置为1，我希望上面蓝色步进器中的数字为1，但它显示的是零而不是1（例如上面的屏幕截图）

我使用@IBAction连接stepperValueChanged方法，并将'value change'作为发送的事件。因此，当stepper.value = 1.0内部触发addToCartButtonDidTapped时，stepperValueChanged方法内部的所有代码都会自动触发

但是，即使我强迫将其设为1，为什么也变为零？你能帮我这个吗？

这是Google驱动器中的文件项目：https://drive.google.com/file/d/1VBR0HkR2Wb2RF2m1CC3zI8a5hJipHW7W/view

这是我的视图控制器代码：

class ViewController: UIViewController, OrderCellDelegate  {

    @IBOutlet weak var collectionView: UICollectionView!

    var order : Order!
    var allProducts = [Product]()

    override func viewDidLoad() {
        super.viewDidLoad()

        order = Order.getOrderFromRealmDatabase()
        allProducts = Product.fetchProductData()

    }

    func stepperValueChange(at selectedIndexPath: IndexPath, stepperValue: Int) {

        guard let userOrder = order else {return}
        let selectedProduct = allProducts[selectedIndexPath.item]

        let maximumQuantityOfProduct = 100
        let minimumQuantityOfProduct = 1

        if stepperValue == minimumQuantityOfProduct - 1 {
            // remove the product from the cart if the stepper value is one below the minimum allowable quantity

            Order.removeProductFromOrderRealmDatabase(userOrder: userOrder, selectedProduct: selectedProduct)
            Product.changeProductQuantityInRealmDatabase(selectedProduct: selectedProduct, quantity: 0)

        } else if stepperValue == minimumQuantityOfProduct {

            // it means add to cart button is tapped

            if userOrder.products.filter("productID == %@", selectedProduct.productID).first == nil {
                Order.addProductToOrderRealmDatabase(userOrder: userOrder, selectedProduct: selectedProduct)
            }  else {
                Order.removeProductFromOrderRealmDatabase(userOrder: userOrder, selectedProduct: selectedProduct)
            }


        } else if stepperValue > minimumQuantityOfProduct && stepperValue <= maximumQuantityOfProduct {

            Product.changeProductQuantityInRealmDatabase(selectedProduct: selectedProduct, quantity: stepperValue)

        }

        collectionView.reloadData()

    }





}


// DATA SOURCE
extension ViewController : UICollectionViewDataSource {

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return allProducts.count
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "orderCell", for: indexPath) as! OrderCell

        cell.productData = allProducts[indexPath.item]
        cell.delegate = self
        cell.indexPath = indexPath

        return cell
    }

}

这是产品代码：

    import RealmSwift


    class Product : Object {

        @objc dynamic var productID : Int = 0
        @objc dynamic var name : String = ""
        @objc dynamic var unitPrice: Double = 0.0
        @objc dynamic var quantityInCart : Int = 0
        @objc dynamic var descriptionProduct : String = ""
        @objc dynamic var hasBeenAddedToCart : Bool = false


        override static func primaryKey() -> String? {


 return "productID"
    }

    convenience init(productID: Int, name: String, unitPrice: Double, descriptionProduct: String) {
        self.init()


        self.productID = productID
        self.name = name
        self.unitPrice = unitPrice
        self.descriptionProduct = descriptionProduct

    }

    static func fetchProductData() -> [Product] {

        let product1 = Product(productID: 1, name: "Product1", unitPrice: 1000, descriptionProduct: "Description of Product 1")
        let product2 = Product(productID: 2, name: "Product2", unitPrice: 2000, descriptionProduct: "Description of Product 2")
        let product3 = Product(productID: 3, name: "Product3", unitPrice: 3000, descriptionProduct: "Description of Product 3")
        let product4 = Product(productID: 4, name: "Product4", unitPrice: 4000, descriptionProduct: "Description of Product 4")
        let product5 = Product(productID: 5, name: "Product5", unitPrice: 5000, descriptionProduct: "Description of Product 5")
        let product6 = Product(productID: 6, name: "Product6", unitPrice: 6000, descriptionProduct: "Description of Product 6")

        return [product1,product2,product3,product4,product5,product6]
    }


    static func changeProductQuantityInRealmDatabase(selectedProduct: Product, quantity: Int) {

        guard let selectedProductInRealmDatabase = RealmService.shared.realm.objects(Product.self).filter("productID == %@", selectedProduct.productID).first else {return}

        RealmService.shared.updateOnCertainKey(object: selectedProductInRealmDatabase, for: ["quantityInCart": quantity])

    }



}

这是订单模型：

class Order : Object {
    @objc dynamic var userID: String = ""
    var products = List<Product>()


    convenience init (userID: String, products: List<Product>) {
        self.init()
        self.userID = "1"
        self.products = products
    }

    //MARK: - Realm Related

    static func getOrderFromRealmDatabase() -> Order {

        let userID = "1"
        let realmService = RealmService.shared.realm
        let allOrder = realmService.objects(Order.self)
        let theOrder = allOrder.filter("userID CONTAINS[cd] %@", userID).first

        if let userOrder = theOrder {
            return userOrder
        } else {
            // Order never setted up before in Realm database container
            // then create Order in realm database

            let newOrder = Order()
            newOrder.userID = userID
            newOrder.products = List<Product>()
            RealmService.shared.save(object: newOrder)
            return newOrder

        }

    }

    static func addProductToOrderRealmDatabase(userOrder: Order, selectedProduct: Product) {


        // check if the selected product has already available in Product.self database or not
        if let matchingProduct = RealmService.shared.realm.objects(Product.self).filter("productID == %@", selectedProduct.productID).first {

            RealmService.shared.save(expression: {
                userOrder.products.append(matchingProduct)
                matchingProduct.hasBeenAddedToCart = true
                matchingProduct.quantityInCart += 1
            })


        } else {

            RealmService.shared.save(expression: {
                userOrder.products.append(selectedProduct)
                selectedProduct.hasBeenAddedToCart = true
                selectedProduct.quantityInCart += 1
            })

        }


    }



    static func removeProductFromOrderRealmDatabase(userOrder: Order, selectedProduct: Product) {


        // to check wheter the selected product from user is already in Order or not

        if let matchingProduct = userOrder.products.filter("productID == %@", selectedProduct.productID).first {

            RealmService.shared.save(expression: {
                matchingProduct.hasBeenAddedToCart = false
                guard let index = userOrder.products.index(where: {$0.productID == matchingProduct.productID}) else {return}
                userOrder.products.remove(at: index)
                matchingProduct.quantityInCart -= 1
            })



        }


    }






}