Swift 4在解除View Controller后调用ViewWillAppear

Question

viewWillAppear在解雇停留后,我想打电话ViewController.

ViewController1- > Segue- >ViewController2

在VeiwController2中

1.)

self.dismiss(animated: true, completion: nil)

2.)

 override func viewDidDisappear(_ animated: Bool) {

       ViewController1().viewWillAppear(true)

    }

在VeiwController1中

什么时候viewWillAppear被称为im得到null错误崩溃我的应用程序.我怎样才能解雇overContext ViewController并viewWillAppear以正确的方式调用该方法.

Answer 1

当您关闭VC2时会自动调用viewWillAppear.删除: ViewController1().viewWillAppear(true)

尝试删除:

super.viewWillAppear(animated)在VC1中. viewDidAppear没有被调用

它甚至会回到你的VC吗？self.dismiss在这里使用"Present Modally"segue.或者使用popViewController嵌入NavigationBar