ios - 从 "Over Current Content"ViewController 返回时如何触发一些代码？

Question

我的应用中有两个ViewController，ViewController和ViewController2

在 ViewController 中，一个按钮设置 Present Modally segue to "ViewController2"

并且 ViewController 覆盖 viewWillAppear

override func viewWillAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    print("will appear")
}

在 ViewController2 中，返回按钮

@IBAction func close(_ sender: Any) {
    self.dismiss(animated: true, completion: nil)
}

现在它仍然可以触发 viewWillAppear 然后我从 ViewController2 返回到 ViewController

如果我将 ViewController2 的显示从 Full Screen 更改为 Over Current Context，viewWillAppear 将不会被触发

返回时如何触发一些代码？

Answer 1

你可以在不放弃 Storyboard转场的情况下做到这一点，但你仍然必须在 ViewCONtroller2 中设置 will/did Disappear 处理程序:

class ViewController: UIViewController {
    ...
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let destination = segue.destination as? ViewController2 {
            (segue.destination as? ViewController2).onViewWillDisappear = {
                //Your code
            }
        }
    }
}

class ViewController2: UIViewController {
    var onViewWillDisappear: (()->())?

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        onViewWillDisappear?()
    }
    ...
}