如何在 Tab Bar Controller 上使用高级导航

Question

我有一个 TabBarController 有 5 个选项。第一个 TabBarItem 是 HomeScreen，第二个是带我进入深度导航工作流。当我在该深度导航的最后一个 ViewController 上时，我有一个 Save 按钮，当我单击它时，我想将用户送回主屏幕。问题是 TabBarController 我的所有图标都消失了。我尝试了另一种解决方案，但对于该解决方案，我的图标显示了，但是当我单击第二个 TabBarItem 时，显示的是深度导航工作流程的最后一个屏幕。这是我的项目：https://github.com/AdvancedNavigationTabBarController 这是我的代码：

第一个标签栏项目

class HomeVC: UIViewController {
    
    @IBOutlet var textfieldHoldingScootersValue: UITextField!
    @IBOutlet var textfieldHoldingBicyclesValue: UITextField!
    
    var valueForScootersScreen = String()
    var valueForBicyclesScreen = String()
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        print("Selected index: \(self.tabBarController?.selectedIndex ?? -1)")
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        
        valueForScootersScreen = textfieldHoldingScootersValue.text ?? String()
        valueForBicyclesScreen = textfieldHoldingBicyclesValue.text ?? String()
        
        if let navController = self.tabBarController?.viewControllers?[1] as? UINavigationController{
            if let scootersTab = navController.children.first as? BuyNewScooterOrBikeVC{
                scootersTab.receivedValueFromHomeScreen = valueForScootersScreen
            }
        }
        
        if let navController = self.tabBarController?.viewControllers?[2] as? UINavigationController{
            if let bicyclesTab = navController.children.first as? BuyNewScooterOrBikeVC{
                bicyclesTab.receivedValueFromHomeScreen = valueForBicyclesScreen
            }
        }
}

第二个标签栏项目

class BuyNewScooterOrBikeVC: UIViewController {
    
    @IBOutlet var receivedValueLabel: UILabel!
    
    var receivedValueFromHomeScreen = String()
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        print("Selected index: \(self.tabBarController?.selectedIndex ?? -1)")
        
        if self.tabBarController?.selectedIndex == 1 {
            receivedValueLabel.text = "Value received for Scooters: \n" + receivedValueFromHomeScreen
            self.navigationItem.title = "Buy a Scooter"
        }

        if self.tabBarController?.selectedIndex == 2 {
            receivedValueLabel.text = "Value received for Bicycles: \n" + receivedValueFromHomeScreen
            self.navigationItem.title = "Buy a Bicycle"
        }
    }
}

第二个标签栏项目的最后一个视图控制器


class ScooterOrBikeLastVC: UIViewController {

    @IBAction func saveBtnTapped(_ sender: UIButton) {
        
        // Navigate to Home Screen
        // self.parent?.navigationController?.popToRootViewController(animated: true) // if I use this line then when I click on the same Tab Bar is sending me to the last screen and I want to be on the first screen of that navigation workflow
        self.navigationController?.popToRootViewController(animated: true) // If I use this line when I click Save btn I don't see anymore the icons on Tab Bar Controller
        self.tabBarController?.selectedIndex = 0
    }
}

感谢阅读本文！

Answer 1

在弹出到 root 之前将 tabIndex 设置为 0。

self.tabBarController?.selectedIndex = 0
self.navigationController?.popToRootViewController(animated: true)

// class ScooterOrBikeLastVC // self.parent?.navigationController?.popToRootViewController(animated: true) // 这行什么都不做，因为父级是 nil 那你为什么会得到“主页”选项卡？因为您已将标签栏设置为 0 self.tabBarController?.selectedIndex = 0

当您希望编写产品代码时，您应该想出更好的方法来在控制器之间进行通信。在您当前的方法中，任何控制器都可以访问和修改另一个控制器。

如何在 Tab Bar Controller 上使用高级导航

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