如何从swift3

Question

我有4个视图控制器，假设A，B，C，D。 ViewController D位于顶部，单击按钮我必须转到ViewController A并删除所有剩余的ViewControllers。如何实现这个

Answer 1

self.navigationController.popToRootViewController(animated: true)

Answer 2

UINavigationController的viewControllers属性是get set属性，这意味着您可以编写自己的视图控制器数组。

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)

Answer 3

如果您正在堆栈中查找一个viewController。我还添加了代码，如果你在堆栈中找不到一个控制器goto mainController或堆栈中的firstController：

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)
    }
}