Swift/UISwitch:如何实现委托/侦听器

问题描述

在UITableViewController中，我有一个自定义单元格，其中包含一个切换器，如下所示:

In my UITableViewController I have a custom cell which contains a switcher which is the following:

import Foundation
import UIKit

class SwitchCell: UITableViewCell {
  @IBOutlet weak var label : UILabel!
  @IBOutlet weak var switchEmail : UISwitch!

  func setEditable(canEdit:Bool) {
      if (canEdit) {
        self.switchEmail.enabled = true
        self.label.highlighted = false
      }
      else {
          self.switchEmail.enabled = false
          self.label.highlighted = true
      }
  }

  func configureCellWithSwitch(labelText:String, switchValue:Bool, enabled:Bool) {

    var labelFrame:CGRect = self.label.frame
    labelFrame.size.height = Settings.labelHeight
    self.label.frame = labelFrame

    self.label.text = labelText

    if (switchValue) {
        self.switchEmail.setOn(true, animated: true)
    }
    else {
        self.switchEmail.setOn(false, animated: true)
    }

    self.setEditable(enabled)

  }
}

我想知道如何实现对切换器的侦听器/代理，以便从UITableViewController获得其值.我能够使用实现方法的UITextField和UITextView为单元格编写委托/侦听器

I would like to know how to implement a listener/delegate to the switcher in order to get its value from the UITableViewController. I was able to write delegate/listeners for a cell with UITextField and UITextView implementing the methods

func controller(controller: UITableViewCell, textViewDidEndEditing: String, atIndex: Int)

和

func controller(controller: UITableViewCell, textFieldDidEndEditingWithText: String, atIndex: Int)

但是我不知道我应该实现什么切换器.

but I don't know what I should implement the switcher.

推荐答案

UISwitch 没有委托协议.您可以听以下状态:

UISwitch has no delegate protocol. You can listen to the status as follows:

ObjC:

// somewhere in your setup:
[self.mySwitch addTarget:self action:@selector(switchChanged:) forControlEvents:UIControlEventValueChanged];


- (void)switchChanged:(UISwitch *)sender {
   // Do something
   BOOL value = sender.on;
}

迅速:

mySwitch.addTarget(self, action: "switchChanged:", forControlEvents: UIControlEvents.ValueChanged)

func switchChanged(mySwitch: UISwitch) {
   let value = mySwitch.on
   // Do something
}

Swift3:

mySwitch.addTarget(self, action: #selector(switchChanged), for: UIControlEvents.valueChanged)

func switchChanged(mySwitch: UISwitch) {
    let value = mySwitch.isOn
    // Do something
}

Swift4:

mySwitch.addTarget(self, action: #selector(switchChanged), for: UIControl.Event.valueChanged)

@objc func switchChanged(mySwitch: UISwitch) {
    let value = mySwitch.isOn
    // Do something
}

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