在 Swift 中使用 UIPageViewController 和 "as" downcast

Question

我正在使用 PageViewController，然后我声明了 PageViewController 的数据源，在实现所需的方法时，我在使用 as downcast 时遇到错误，它说 "correctViewController is not a type."

import UIKit

class HarishPageViewController: UIPageViewController, UIPageViewControllerDataSource {

override func viewDidLoad() {
    super.viewDidLoad()
    self.dataSource = self
    // Do any additional setup after loading the view.
}

let pageTitles = ["HarishIntroduction", "HarishPlaces", "WyomingSeminary", "AppleTree", "KearneyHighSchool", "MosconeCenter"]
let viewControllerArray: NSArray = [HarishIntroduction(), HarishPlaces(), WyomingSeminary(), AppleTree(), KearneyHighSchool(), MosconeCenter()]
var index = 0

func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
    if index == 0 {
        return nil
    }
    else {
        index--
        let page = pageTitles[index]
        let correctViewController: UIViewController = viewControllerArray[index] as! UIViewController
        let vc = harishStoryboard.instantiateViewControllerWithIdentifier(page) as correctViewController

    }
}

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

我尝试了很多不同的方法，但就是无法摆脱 as 旁边的错误。有什么想法吗？

Answer 1

它不是类型或 class。您正在尝试向下转换为变量。

在 as 之后，只需写入控制器的 class

在 Swift 中使用 UIPageViewController 和 "as" downcast

Using UIPageViewController in Swift with "as" downcast

swift

uipageviewcontroller