Xcode 7/Swift：保存滑块的值并在视图更改时发送到 child class

Question

我试图让某个视图上的滑块值显示在 child 视图上的文本框中。但是当加载第二个视图时，滑块的值似乎丢失并设置为零。我将如何在视图更改之前保留该滑块的值，以便使用 child 视图中的最新值？这是一些相关代码（我想将文本框 "redTextBox" 设置为 "changeRed" 滑块的值）：

PARENTCLASS--------------------------------

class ViewController: UIViewController {

@IBOutlet weak var changeRed: UISlider!
@IBOutlet weak var changeGreen: UISlider!
@IBOutlet weak var changeBlue: UISlider!

var r: Float = 0
var g: Float = 0
var b: Float = 0

@IBAction func slideRed(sender: AnyObject) {
    self.view.backgroundColor = UIColor(colorLiteralRed: changeRed.value, green: changeGreen.value, blue: changeBlue.value, alpha: 1.0)
     r = changeRed.value
     g = changeGreen.value
     b = changeBlue.value
}

@IBAction func slideGreen(sender: AnyObject) {
  self.view.backgroundColor = UIColor(colorLiteralRed: changeRed.value, green: changeGreen.value, blue: changeBlue.value, alpha: 1.0)
     r = changeRed.value
     g = changeGreen.value
     b = changeBlue.value

}

@IBAction func slideBlue(sender: AnyObject) {
      self.view.backgroundColor = UIColor(colorLiteralRed: changeRed.value, green: changeGreen.value, blue: changeBlue.value, alpha: 1.0)
     r = changeRed.value
     g = changeGreen.value
     b = changeBlue.value

}
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = UIColor(colorLiteralRed: changeRed.value, green: changeGreen.value, blue: changeBlue.value, alpha: 1.0)
}

......
}

CHILD CLASS----------------------------

class ColorValueVC: ViewController {

@IBOutlet weak var redTextBox: UITextField!
@IBOutlet weak var greenTextBox: UITextField!
@IBOutlet weak var blueTextBox: UITextField!

override func viewDidLoad() {
    //super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    redTextBox.text = "\(changeRed.value)"
}

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


}

Answer 1

您的 child 继承自 parent 视图控制器。你想通过这样做达到什么目的？如果它们是两个视图控制器，其中一个连接到另一个，那么它们之间不应该有继承 link 。相反，您通过在 A.

中实现 prepareForSegue 将数据从 A 传递到 B

Xcode 7/Swift：保存滑块的值并在视图更改时发送到 child class

Xcode 7/Swift: Save value of slider and send to child class when view changes

xcode

ios

swift