Ios 如何使用通知中心将数据从FirstTableView发送到SecondTableView而不使用segue

当我试图使用NotificationCenter设计模式将一个数组从UITableView传递到另一个UITableView时，我遇到了一个问题（因为我在这两个UIViewController之间没有分段）。我不知道我做错了什么，但我在第二个视图控制器中没有收到任何数据

我的函数如下所示：

*第一个VC-发送方控制器（从那里发送数据）*

class ProductsViewController: UIViewController{

var selectedProductsArray = [Product]()

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)


        // Implement Notification Design Pattern to send data
        NotificationCenter.default.post(name: NSNotification.Name(rawValue: "productsToLoad"), object: selectedProductsArray)

        print(selectedProductsArray) // Here I have some data in this array (Photo here: https://ibb.co/k8hoEy)
    }

class CartViewController: UIViewController {

var productsInCartArray = [Product]()

 // We retrieve data from "selectedProductsArray" and we append all the products into "productsInCartArray"
    @objc func notificationRecevied(notification: Notification) {
        productsInCartArray = notification.object as! [Product]
        print(productsInCartArray)
    }

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        // Add observer to watch when something was changed in "selectedProductsArray"
        NotificationCenter.default.addObserver(self, selector: #selector(notificationRecevied(notification:)), name: NSNotification.Name(rawValue: "productsToLoad"), object: nil)

       print(productsInCartArray) // Output: []

    }

override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        // We remove the observer from the memory
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name(rawValue: "productsToLoad"), object: nil)
    }

}

*第二视图控制器-接收器控制器（我将在其中接收数据）*

class ProductsViewController: UIViewController{

var selectedProductsArray = [Product]()

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)


        // Implement Notification Design Pattern to send data
        NotificationCenter.default.post(name: NSNotification.Name(rawValue: "productsToLoad"), object: selectedProductsArray)

        print(selectedProductsArray) // Here I have some data in this array (Photo here: https://ibb.co/k8hoEy)
    }

class CartViewController: UIViewController {

var productsInCartArray = [Product]()

 // We retrieve data from "selectedProductsArray" and we append all the products into "productsInCartArray"
    @objc func notificationRecevied(notification: Notification) {
        productsInCartArray = notification.object as! [Product]
        print(productsInCartArray)
    }

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        // Add observer to watch when something was changed in "selectedProductsArray"
        NotificationCenter.default.addObserver(self, selector: #selector(notificationRecevied(notification:)), name: NSNotification.Name(rawValue: "productsToLoad"), object: nil)

       print(productsInCartArray) // Output: []

    }

override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        // We remove the observer from the memory
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name(rawValue: "productsToLoad"), object: nil)
    }

}

截图：

---

如果您正在阅读此文章，感谢您抽出时间

您需要从

CartViewController的
视图中删除此项

NotificationCenter.default.removeObserver(self, name: NSNotification.Name(rawValue: "productsToLoad"), object: nil)

let products = ((self.tabBarController?.viewControllers![0] as! UINavigationController).topViewController as! ProductsViewController).selectedProductsArray 

当您在产品中发布时，卡不会显示，因此其中没有侦听器，除此之外，
CartViewController
应在发布来自
ProductsViewController
的任何数据之前至少打开一次

NotificationCenter.default.removeObserver(self, name: NSNotification.Name(rawValue: "productsToLoad"), object: nil)

let products = ((self.tabBarController?.viewControllers![0] as! UINavigationController).topViewController as! ProductsViewController).selectedProductsArray 

//

您可以完全删除
NotificationCenter
工作，然后在
CartViewController

NotificationCenter.default.removeObserver(self, name: NSNotification.Name(rawValue: "productsToLoad"), object: nil)

let products = ((self.tabBarController?.viewControllers![0] as! UINavigationController).topViewController as! ProductsViewController).selectedProductsArray 

注意：
不要为
担心展开它不会崩溃
是的，这正是您所说的。如何解决此问题，因为我不想在FirstView和SecondView之间浏览两次以查看数据。谢谢你的回答！没有检索任何数据，当我从SecondTab返回到FirstTab时崩溃，出现以下错误：“无法将类型为'UINavigationController'（0x10FFFF18）的值强制转换为'ShoppingLand.ProductsViewController'（0x10d167668）。”现在不再崩溃，而是我的secondArray（“产品”）崩溃是空的，当我在购物车中添加1个项目时，在我的第一个数组中，该项目添加了2次。所以我添加了1台iPhoneX，我的阵列中会有2台iPhoneX。对不起，我在视图中调用了你的代码将消失…哈哈。只使用一行代码！！！非常感谢您的时间！！！Happy coding=DI回答了类似的问题@