Swift 页面跳转

    
override func viewDidLoad() {
    super.viewDidLoad()
    
    // Do any additional setup after loading the view.
    // 每次当前视图控制器创建一次，全局变量加一
    pageNum = pageNum + 1
    //        根据当前的全局变量名设置标题
    self.title = "Page\(pageNum)"
    self.view.backgroundColor = UIColor.purple
    // 添加一个页面跳转按钮
    let push = UIButton(frame: CGRect(x: 40, y: 120, width: 240, height: 40))
    push.setTitle("Push page", for: UIControl.State())
    push.backgroundColor = UIColor.orange
    push.addTarget(self, action: #selector(pushPage), for: UIControl.Event.touchUpInside)
    self.view.addSubview(push)
    
    // 添加一个按钮，点击时返回上一个页面
    let pop = UIButton(frame: CGRect(x: 40, y: 180, width: 240, height: 40))
    pop.setTitle("Pop Page", for: UIControl.State())
    pop.backgroundColor = UIColor.orange
    pop.addTarget(self, action: #selector(popPage), for: UIControl.Event.touchUpInside)
    self.view.addSubview(pop)
    
    // 添加一个按钮，点击时跳转到已经push但未pop的指定序号的页面
    let index = UIButton(frame: CGRect(x: 40, y: 280, width: 240, height: 40))
    index.setTitle("Goto Index Page", for: UIControl.State())
    index.backgroundColor = UIColor.orange
    index.addTarget(self, action: #selector(gotoIndexPage), for: UIControl.Event.touchUpInside)
    self.view.addSubview(index)
    
    // 添加一个按钮，点击时跳转到根视图
    let root = UIButton(frame: CGRect(x: 40, y: 340, width: 240, height: 40))
    root.setTitle("Goto root Page", for: UIControl.State())
    root.backgroundColor = UIColor.orange
    root.addTarget(self, action: #selector(gotoRootPage), for: UIControl.Event.touchUpInside)
    self.view.addSubview(root)
}
    
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
    
// 创建第一个按钮绑定的方法打开页面（入栈）
@objc func pushPage(){
// 实例化第二个视图控制器
let viewController = FirstViewController()
// 把视图压入导航视图
self.navigationController?.pushViewController(viewController, animated: true)
}
// 第二个按钮的方法，将导航视图控制器从堆栈中移除
@objc func popPage(){
    self.navigationController?.popViewController(animated: true)
}
// 第三个按钮绑定的方法，根据全局序号，查找堆栈中指定序号2的视图控制器
@objc func gotoIndexPage(){
    let viewController = self.navigationController?.viewControllers[2]
    self.navigationController?.popToViewController(viewController!, animated: true)
}
// 创建第四个按钮绑定的方法,所有子视图出栈
@objc func gotoRootPage(){
    self.navigationController?.popToRootViewController(animated: true)
}

参考资料：https://blog.csdn.net/weixin_41735943/article/details/81142709