從子ViewController報告更改

Question

如果一個ViewController從另一個ViewController繼承，我該如何更新子ViewController中的東西，因爲父ViewController中的變量發生了變化？

class ViewControllerOne: UIViewController { 

    var timer = Timer() 

    var number: Int = 0 

    func updateNumber() { 
     number += 1 
    } 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateNumber), userInfo: nil, repeats: true) 
    } 
} 



class ViewControllerTwo: ViewControllerOne { 
    // So in this class I want to print to the console when number is 3. 
    // How do I check for that from this class? 
} 

Answer 1

替代updateNumber的ViewControllerTwo。

override func updateNumber() { 
    super.updateNumber() 

    if number == 3 { 
     // do something 
    } 
}