ios - 将 instantiateViewController 与 UIVewController 结合使用时获取信号 SIGABRT

Question

我希望有人能帮助我解决我遇到的这个问题。

我正在尝试将UIViewController数组添加到UIPageViewController。但是，每当我尝试通过方法 instantiateViewController 访问 View Controller 时，都会收到 SIGABRT 错误。

let vc: UIViewController = self.storyboard?.instantiateViewController(withIdentifier: views[index]) as! UIPageViewController

这是我的整个 ViewController.swift 文件，仅供引用。

import UIKit

class ViewController: UIViewController {

    var pageViewController: UIPageViewController!
    var views: [String] = ["view1","view2"]

    override func viewDidLoad() {
        super.viewDidLoad()

        self.pageViewController = self.storyboard?.instantiateViewController(withIdentifier: "pageViewController") as! UIPageViewController

        var arr: [UIViewController] = []

        for i in 0..<views.count{

            arr.append(assignView(index: i))

        }

        self.pageViewController.setViewControllers(arr, direction: .forward, animated: true, completion: nil )

        self.addChildViewController(self.pageViewController)
        self.view.addSubview(self.pageViewController.view)
        pageViewController.didMove(toParentViewController: self)

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func assignView (index: Int) -> UIViewController{

        let vc: UIViewController = self.storyboard?.instantiateViewController(withIdentifier: views[index]) as! UIPageViewController

        return vc

    }


}

有人可以告诉我为什么我的代码会抛出这个错误吗？

非常感谢!

Answer 1

从下面一行:self.storyboard?.instantiateViewController(withIdentifier: "pageViewController") as! UIPageViewController

Storyboard似乎被视为可选。当您尝试访问 Storyboard 变量时，它可能会变得为零。理想情况下，它不应该为零，也不应该是可选的。如果该选项是有意完成的，那么您可以在访问之前应用“if let”进行检查。

如果您需要进一步说明，请告诉我。