如何从swift3删除所有viewControllers除堆栈之外

Question

我有4个视图控制器假设A，B，C，D。 ViewController D在顶部，点击按钮我必须去ViewController A并删除所有剩下的ViewController。如何实现这个

Answer 1

self.navigationController.popToRootViewController(animated: true) 

Answer 2

如果你正在寻找一个viewController在堆栈中。我还添加了代码，如果你找不到，在在堆栈中的堆栈转到mainController或firstController一个控制器：

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属性get set财产，这意味着你可以写您自己的视图控制器阵列。

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)