xcode - 使用 Segue 自动加载 SecondViewController

Question

如何在 viewDidLoad() 方法中与 ViewController 同时加载 SecondViewController ？

Segue 的类型是 Sheet。

import Cocoa

class ViewController: NSViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        self.performSegue(withIdentifier: "secondVC", sender: self)
    }

    func prepareforSegue(segue: NSStoryboardSegue, sender: Any?) {
        if let identifier = segue.identifier, identifier == "secondVC" {
            _ = segue.destinationController as? SecondViewController
        }
    }
}

Answer 1

这个

self.performSegue(withIdentifier: "secondVC", sender: self)

在 viewDidLoad 中不起作用，请考虑将其包装在 viewDidAppear 中的 Dispatch-after 或 bool 标志内

DispatchQueue.main.asyncAfter(deadline:.now() + 2 ) {
   self.performSegue(withIdentifier: "secondVC", sender: self)
}

或

var once = true
override func viewDidAppear() {
   super.viewDidAppear()
   if once {
        self.performSegue(withIdentifier: "secondVC", sender: self)
        once = false
   }
}