ios - 无法以编程方式在 Swift 中创建 UIViewController

Question

当我尝试在 Swift 中创建 UIViewController 的实例时，所有继承的初始化程序都不可用，即使我没有在 View 中定义任何指定的初始化程序 Controller (或其他任何东西，FWIW)。

此外，如果我尝试通过将其设为 Root View Controller 来显示它，它永远不会显示:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        // Override point for customization after application launch.

        window = UIWindow(frame: UIScreen.mainScreen().bounds)
        window?.makeKeyAndVisible()
        window?.backgroundColor = UIColor.greenColor()



        let vc = ImageViewController()
        window?.rootViewController = vc

        return true
    }

View Controller 的代码只是 Xcode 的模板:

import UIKit

class ImageViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

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


    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}

有人知道这是怎么回事吗？？？？

Answer 1

正如您所指出的:只要 nib 名称与 objective-C 中的类名称相匹配，即使您在初始化 View Controller 时未指定 nib 名称， View Controller 仍将 look for the nib file whose name matches the name of the view controller class .

但由于某些原因(也许是一个错误)，在 Swift 中情况并非如此。

而不是写:

let vc = ImageViewController()

初始化 View Controller 时必须明确指定接口(interface):

let vc = ImageViewController(nibName: "nibName", bundle: nil)