如何将一组新的视图控制器从一个选项卡推送到另一个选项卡？

Question

我有一个带有 2 个标签的 tabBarController。每个选项卡内都有一个navigationController。每个navigationController 有3 个孩子viewControllers

                           tabBarController
                            /            \
                        tabOne          tabTwo
                         /                  \
                  NumNavController     ColorNavController
                       |                      |
                    ViewOne                ViewBlack
                       |                      |
                    ViewTwo                 ViewRed
                       |                      |
                   ViewThree               ViewPurple//(beginning)
                                              |
                                           myButton
                               //myButton pushes on ViewOne>ViewTwo>ViewThree(end)

我在 ViewPurple 中有一个按钮，按下时我想按下 ViewOne、ViewTwo 和 ViewThree。

(beginning)ViewPurple > ViewOne > ViewTwo > ViewThree(end)

因此，我会从 ViewThree 退回到 ViewPurple-这就是我想要实现的目标

(beginning)ViewPurple < ViewOne < ViewTwo < ViewThree(end)

在 ViewPurple 中，我将 ColorNavController 重置为 NumNavController 的子控制器。

let numVCs = [viewThreeVC, viewTwoVC, viewOneVC]
self.navigationController?.setViewControllers(numVCs, animated: true)
//Apple docs says to set them backwards
//The view controllers to place in the stack. The front-to-back order of the controllers in this array represents the new bottom-to-top order of the controllers in the navigation stack. Thus, the last item added to the array becomes the top item of the navigation stack

我遇到的问题是，一旦我按下 ViewOne 并按下后退按钮而不是进入 ViewPurple，我最终会进入 ViewTwo。它陷入了奇怪的循环，它似乎不再知道开始的 viewController 在哪里。

 //I can't push back to ViewPurple
 ViewOne < ViewTwo < ViewOne < ViewTwo < ViewThree(end)

问题出在哪里以及如何返回 ViewPurple？

ViewPurple：（第一种方式 - 没有崩溃但奇怪的循环）

class ViewPurple: UIViewController {

@IBAction func myButton(sender: UIButton){
     self.presentNewVCs()
  }

func presentNewVCs(){
     let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
     let viewOneVC = mainStoryboard.instantiateViewControllerWithIdentifier("ViewOne") as! ViewOneController
     let viewTwoVC = mainStoryboard.instantiateViewControllerWithIdentifier("ViewTwo") as! ViewTwoController
     let viewThreeVC = mainStoryboard.instantiateViewControllerWithIdentifier("ViewThree") as! ViewThreeController

     let numVCs = [viewThreeVC, viewTwoVC, viewOneVC]
     self.navigationController?.setViewControllers(numVCs, animated: true)
  }
}

我还尝试了第二种方式来呈现 NumNavController，但我不断收到异常 'Application tried to present modally an active controller。我对 ViewPurple 做了一个弱引用并试图取消它，但它仍然崩溃了

ViewPurple：（第二种方式 - 崩溃）

class ViewPurple: UIViewController {

weak var parent:ViewPurple!

@IBAction func myButton(sender: UIButton){
     self.presentNewVCs()
  }

func presentNewVCs(){

     let numNavController = self.tabBarController!.viewControllers![0] as! NumNavController

     let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
     let viewOneVC = mainStoryboard.instantiateViewControllerWithIdentifier("ViewOne") as! ViewOneController
     let viewTwoVC = mainStoryboard.instantiateViewControllerWithIdentifier("ViewTwo") as! ViewTwoController
     let viewThreeVC = mainStoryboard.instantiateViewControllerWithIdentifier("ViewThree") as! ViewThreeController

     let numVCs = [viewThreeVC, viewTwoVC, viewOneVC]
     numNavController.setViewControllers(numVCs, animated: true)
     self.presentViewController(numNavController, animated: true, completion: nil)
  }

  deinit{
     self.parent = nil
  }
}

Answer 1

能否请您更新您的buttonAction:

@IBAction func myButton(sender: UIButton){ 
     let viewOneVC =  mainStoryboard.instantiateViewControllerWithIdentifier("ViewOne") as! ViewOneController 
    self.navigationController.pushViewController(viewOneVC, animate:true) 
}

Answer 2

首先你不能显示NumNavController，因为那已经是tabBarController的一部分了。

当setViewControllers 被调用时，它会完全替换navigationViewController 的viewcontroller 堆栈，因此您还需要在numVCs 数组中添加ViewPurple 并将ViewPurple 设置为您的根视图控制器。

那么，在调用popToRootViewController 时将移回ViewPurple。