UISegmentedControl取消选择未在代码识别虽然是在视觉上

Question

我有我使用的代码从该柱子类5段segmentedControl：

How to deselect a segment in Segmented control button permanently till its clicked again

，以允许取消所述控制器当第二次触摸所选段。

这可以直观地工作，但是当试图分配一个UserDefault时，它只是被识别为被触摸了两次的段。

我无法弄清楚我可以添加到子类代码或viewController代码，使其工作。

任何帮助，将不胜感激。

子类代码：

class mySegmentedControl: UISegmentedControl { 
    @IBInspectable var allowReselection: Bool = true 

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) { 
     let previousSelectedSegmentIndex = self.selectedSegmentIndex 
     super.touchesEnded(touches, with: event) 
     if allowReselection && previousSelectedSegmentIndex == self.selectedSegmentIndex { 
      if let touch = touches.first { 
       let touchLocation = touch.location(in: self) 

       if bounds.contains(touchLocation) { 
        self.sendActions(for: .valueChanged) 
        self.selectedSegmentIndex = UISegmentedControlNoSegment 
       } 
      } 
     } 
    } 

}

视图控制器CODE：

所有的

@IBOutlet weak var METDome_L: UISegmentedControl! 
let key_METDome_L = "METDome_L" 
var METD_L: String! 

@IBAction func METDome_Lselect(_ sender: Any) { 
    if METDome_L.selectedSegmentIndex == 0{ 
     METD_L = "1" 
     UserDefaults.standard.set(METD_L, forKey: key_METDome_L) 
    } 
    else if METDome_L.selectedSegmentIndex == 1{ 
     METD_L = "2" 
     UserDefaults.standard.set(METD_L, forKey: key_METDome_L) 
    } 
    else if METDome_L.selectedSegmentIndex == 2{ 
     METD_L = "3" 
     UserDefaults.standard.set(METD_L, forKey: key_METDome_L) 
    } 
    else if METDome_L.selectedSegmentIndex == 3{ 
     METD_L = "4" 
     UserDefaults.standard.set(METD_L, forKey: key_METDome_L) 
    } 
    else if METDome_L.selectedSegmentIndex == 4{ 
     METD_L = "5" 
     UserDefaults.standard.set(METD_L, forKey: key_METDome_L) 
    } 
    else{ 
     METD_L = "NONE" 
     UserDefaults.standard.set(METD_L, forKey: key_METDome_L) 
    } 
} 

Answer 1

首先，如果你继承你必须使用该类型来获取增强的功能控制。

@IBOutlet weak var METDome_L: MySegmentedControl! // class names start with a capital letter 

添加属性selectionKey和UserDefaults保存状态UISegmentedControlNoSegment（如Int）当控制被取消选择。如果属性为空（必须在使用该子类的视图控制器中设置），则引发fatal error。

class MySegmentedControl: UISegmentedControl { 
    @IBInspectable var allowReselection: Bool = true 

    var selectionKey = "" 

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) { 
     let previousSelectedSegmentIndex = self.selectedSegmentIndex 
     super.touchesEnded(touches, with: event) 
     if allowReselection && previousSelectedSegmentIndex == self.selectedSegmentIndex { 
      if let touch = touches.first { 
       let touchLocation = touch.location(in: self) 

       if bounds.contains(touchLocation) { 
        self.sendActions(for: .valueChanged) 
        self.selectedSegmentIndex = UISegmentedControlNoSegment 
        guard !selectionKey.isEmpty else { fatalError("selectionKey must not be empty") 
        UserDefaults.standard.set(UISegmentedControlNoSegment, forKey: selectionKey) 
       } 
      } 
     } 
    } 
} 

在您的视图控制器设置属性selectionKey在viewDidLoad到自定义按键和控制的选中状态保存到UserDefaults在IBAction。不要任何数学。第一个段是索引为0的段0。习惯于从零开始的索引。这使恢复选定状态更方便。

@IBOutlet weak var METDome_L: MySegmentedControl! 
let key_METDome_L = "METDome_L" 

override func viewDidLoad() 
{ 
    super.viewDidLoad() 
    METDome_L.selectionKey = key_METDome_L 
} 

@IBAction func METDome_Lselect(_ sender: UISegmentedControl) { 
    UserDefaults.standard.set(sender.selectedSegmentIndex, forKey: key_METDome_L) 
}