如何從swift3刪除所有viewControllers除堆棧之外

Question

我有4個視圖控制器假設A，B，C，D。 ViewController D在頂部，點擊按鈕我必須去ViewController A並刪除所有剩下的ViewController。如何實現這個

Answer 1

self.navigationController.popToRootViewController(animated: true) 

Answer 2

如果你正在尋找一個viewController在堆棧中。我還添加了代碼，如果你找不到，在在堆棧中的堆棧轉到mainController或firstController一個控制器：

if let viewControllers = self.navigationController?.viewControllers { 
    var element_count = 0 
    for controller in viewControllers { 
     if controller is YourViewController { 
      element_count = 1 
      self.navigationController?.popToViewController(controller, animated: true) 
      break 
     } 
    } 
    if element_count != 1{ 
     _ = self.navigationController?.popToRootViewController(animated: true) 
    } 
} 

Answer 3

的UINavigationController的viewControllers屬性get set財產，這意味着你可以寫您自己的視圖控制器陣列。

例如，

let VCs = self.navigationController.viewControllers //VCs = [A, B, C, D] 

let vcA = VCs[0] //vcA = A 
//finally 
self.navigationController.viewControllers = [vcA] //done 
// OR 
self.navigationController.setViewControllers([vcA], animated: true)