从模态呈现的视图控制器导航到根视图控制器

Question

我有以下情况。

根viewcontroller-A

推入 viewcontroller - B

呈现 viewcontroller - C

A -> 推 B。

B -> 呈现 C.

如何从C回到A

Answer 1

你可以在C里面写如下

let presenting = self.presentingViewController ?? self.navigationController?.presentingViewController
let navCtrl1 = presenting as? UINavigationController // in case you presented C using b.navigationController.present...
let navCtrl2 = presenting?.navigationController // in case you presented c using b.present...
if let navCtrl = navCtrl1 ?? navCtrl2  {
    self.dismiss(animated: true, completion: {
        navCtrl.popToRootViewController(animated: true)
    })
}

更新

I would like to know if is there anyway to bypass the dismiss and direct pop to root view controller. I want to avoid showing View-controller B

let presenting = self.presentingViewController ?? self.navigationController?.presentingViewController
let navCtrl1 = presenting as? UINavigationController // in case you presented C using b.navigationController.present...
let navCtrl2 = presenting?.navigationController // in case you presented c using b.present...
if let navCtrl = navCtrl1 ?? navCtrl2  {
    navCtrl.popToRootViewController(animated: false)
    self.dismiss(animated: true, completion: nil)
}

Answer 2

怎么办？

为此，您必须将呈现控制器 UINavigationController 作为变量传递给您正在 present 的视图控制器。让我告诉你怎么做，以及结果。

从 vcA 推进到 vcB 是相当直接的。需要注意的一件事是，当您从 vcA 推送到 vcB 时，vcA 将位于导航堆栈中。考虑到这一点，让我移动一个。

首先对 vcC 进行更改，方法是添加一个变量来保存呈现 vcC 的视图控制器的 UINavigationCongroller，即 vcB。做如下（阅读评论）

class ViewControllerC: UIViewController {

    // Variable that holds reference to presenting ViewController's Navigtion controller
    var presentingNavigationController: UINavigationController!

    //Some action that triggers the "Go-back-to-A"
    @objc func pressed() {
        // When the completion block is executed in dismiss,
        // This function will loop through all ViewControllers in the presenting Navigation stack to see if vcA exists
        // Since vcA was earlier pushed to the navigation stack it should exist
        // So we can use the same navigation controller to pop to vcA    
        // Set the animated property to false to make the transition instant
        dismiss(animated: false) {
            self.presentingNavigationController.viewControllers.forEach({
                if let vc = [=10=] as? ViewController {
                    self.presentingNavigationController.popToViewController(vc, animated: true)
                }
            })
        }
    }

并且在 vcB 中，您可以将以下内容添加到 present(_:_:_:) 函数

// function call
@objc func pressed() {
    let vc = ViewControllerC()
    // Setting the navigation controller for reference in the presented controller
    vc.presentingNavigationController = self.navigationController  
    present(vc, animated: true, completion: nil)
}

从模态呈现的视图控制器导航到根视图控制器

Navigate to root view-controller from modally presented view controller

uinavigationcontroller

pushviewcontroller

ios

presentviewcontroller

swift

更新

怎么办？

结果