以编程方式显示 ViewController（不工作）

Question

我有一个名为“ViewController.swift”的主 VC，它与 Main.storyboard 中的 ViewController 场景绑定。 然后我想要另一个屏幕，它显示我的 ViewController.swift 中的条件何时满足。 因此，我得到了一个 Gameover.storyboard，它有一个带有 Storyboard ID“overID”的 VC 场景以及一个用于处理 GameOver 场景的“GameoverViewController.swift”。

这是我在 ViewController.swift 中的代码，当满足以下条件时，它应该会打开 Gameover.storyboards VC 场景：

       import UIKit

        class ViewController: UIViewController {
            var wantedLiter = 10.00
            var timer : Timer?
            var actualLiter = 0.00
            var timerReset = true
            var preisProLiter = 1.26


//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


            let storyBoard: UIStoryboard = UIStoryboard(name: "Gameover", bundle: nil)

            let gameoverViewController = storyBoard.instantiateViewController(withIdentifier: "overID") as! GameoverViewController 

//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

            @IBOutlet weak var preisliterLabel: UILabel!
            @IBOutlet weak var euroLabel: UILabel!
            @IBOutlet weak var numberLabel: UILabel!
            @IBOutlet weak var numberButton: UIButton!
            @IBOutlet weak var confirmButton: UIButton!


            @IBAction func confirm(_ sender: Any) {

            }

            override func viewDidLoad() {
                super.viewDidLoad()
                numberLabel.text = String(round(1000*actualLiter)/1000) //initial value
                preisliterLabel.text = String(preisProLiter)
                // Do any additional setup after loading the view.
            }

            @IBAction func holdingTheButton(_ sender: Any) {
                print("I am holding")
                       timerReset = false // reset to false since you are holding the button
                       guard timer == nil else { return }
                       timer = Timer.scheduledTimer(timeInterval: 0.005, target: self, selector: #selector(updateTime), userInfo: nil, repeats: true)
            }


            @IBAction func buttonReleased(_ sender: Any) {
                print("button released")
                if (wantedLiter == actualLiter){
                    print("WIN!")
                    actualLiter = 0;
                }
               //startTime = 0.00
                 timer?.invalidate()
                 timer = nil
               // timerReset = true // reset to true since you released.
            }


            @objc func updateTime(){
                //update label every second

                print("updating label ")
                if (wantedLiter <= actualLiter){
                    print("Ooops")
                    actualLiter = 0; 

//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


self.present(gameoverViewController, animated: true, completion: nil) 

//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

                }

               actualLiter += 0.01
               numberLabel.text = String(round(1000*actualLiter)/1000)
               euroLabel.text = String((round(100*actualLiter*preisProLiter)/100))

            }
        }

现在为您提供了一些屏幕截图，这可能会有所帮助。

如果您需要更多屏幕，请询问。

现在，我收到以下错误：

1) ViewController.swift 上部标有“！！！...”

不能在属性初始化器中使用实例成员“storyBoard”；属性初始化器在“self”可用之前运行

2) ViewController.swift

无法将“gameoverViewController.Type”类型的值转换为预期的参数类型“UIViewController”

3) ViewController.swift 上半部分：

使用未声明的类型“GameoverViewController”

这就是我更改代码的方式：

import UIKit

class ViewController: UIViewController {
    var wantedLiter = 10.00
    var timer : Timer?
    var actualLiter = 0.00
    var timerReset = true
    var preisProLiter = 1.26


   let storyBoard: UIStoryboard = UIStoryboard(name: "Gameover", bundle: nil)
    var gameoverViewController: GameoverViewController!

    @IBOutlet weak var preisliterLabel: UILabel!
    @IBOutlet weak var euroLabel: UILabel!
    @IBOutlet weak var numberLabel: UILabel!
    @IBOutlet weak var numberButton: UIButton!
    @IBOutlet weak var confirmButton: UIButton!


    @IBAction func confirm(_ sender: Any) {

    }

    override func viewDidLoad() {
        super.viewDidLoad()
        gameoverViewController = storyBoard.instantiateViewController(withIdentifier: "overID") as? GameoverViewController

        numberLabel.text = String(round(1000*actualLiter)/1000) //initial value
        preisliterLabel.text = String(preisProLiter)
        // Do any additional setup after loading the view.
    }

    @IBAction func holdingTheButton(_ sender: Any) {
        print("I am holding")
               timerReset = false // reset to false since you are holding the button
               guard timer == nil else { return }
               timer = Timer.scheduledTimer(timeInterval: 0.005, target: self, selector: #selector(updateTime), userInfo: nil, repeats: true)
    }


    @IBAction func buttonReleased(_ sender: Any) {
        print("button released")
        if (wantedLiter == actualLiter){
            print("WIN!")
            actualLiter = 0;
        }
       //startTime = 0.00
         timer?.invalidate()
         timer = nil
       // timerReset = true // reset to true since you released.
    }


    @objc func updateTime(){
        //update label every second

        print("updating label ")
        if (wantedLiter <= actualLiter){
            print("Ooops")
            actualLiter = 0;
            self.present(gameoverViewController as! UIViewController, animated: true, completion: nil)
        }

       actualLiter += 0.01
       numberLabel.text = String(round(1000*actualLiter)/1000)
       euroLabel.text = String((round(100*actualLiter*preisProLiter)/100))

    }
}

（不工作）

我将 GameoverViewController 类型更改为 UIViewController。

但是我的错字在哪里？ （G 而不是 g）？

Answer 1

1. 将gameoverViewController 的初始化器移动到viewDidLoad 或类似的位置，并使gameoverViewController 成为可选或隐式展开的可选（即类型后的!）

2. 应该由 1 固定。

3. 如果这也没有被 1. 修复，请显示 GameoverViewController 的源代码。