Question

我已经在这个问题上寻找解决方案，但似乎没有一个能用于我的用例。

我在viewcontroller中有一个表，我面临的问题是当滚动UISwitch状态时会重置为OFF。我理解表格单元格可以重复使用，但是当用户根据下面的代码滚动时，如何实现一个能够恢复UISwitch状态的解决方案

import UIKit

class StirrViewController: UIViewController, UITableViewDelegate, UITableViewDataSource{

@IBOutlet weak var mylabel: UILabel!
var myString = String()

@IBAction func stirrBtn(_ sender: AnyObject) {
}

var timeSelected = String()
var selectedTimeArr = [String]()

override func viewDidLoad() {
    super.viewDidLoad()
    mylabel.text = myString
    self.timeSelected = myString
}

func switchChanged(_ sender : UISwitch!){
    print("table row switch Changed \(sender.tag)")
    print("The switch is \(sender.isOn ? "ON" : "OFF")")
    let kValue = (sender.tag + 1)
    let keyValue = String(kValue)
    if sender.isOn {
        recipeSettings.boolStirrSwitch[keyValue] = true
        recipeSettings.switchedOnArr.append(keyValue)

    } else {
        recipeSettings.boolStirrSwitch[keyValue] = false
    }
}

public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
    let stringNum = Int(self.timeSelected)
    recipeSettings.recipeTimeSet2 = stringNum!
    return(stringNum)!
}


public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
    var cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! UITableViewCell
    //here is programatically switch make to the table view
    let switchView = UISwitch(frame: .zero)
    switchView.setOn(false, animated: true)
    switchView.tag = indexPath.row // for detect which row switch Changed
    switchView.addTarget(self, action: #selector(self.switchChanged(_:)), for: .valueChanged)
    cell.accessoryView = switchView

    // Process data displayed in rows(minutes)
    let endTime = Int(self.timeSelected)
    let startTime = Int(1)

    // Recipe time array
    let timeArray: [Int]  = Array(startTime...endTime!)
    let stringTimeArr = timeArray.map{String($0)}

    // Save time array to global variable
    recipeSettings.recipeTimeSetArr = stringTimeArr

    // Create a boolean Array to hold all default false booleans
    let defBool: Bool = false
    var defBoolArr: [Bool] = []

    // Fill the array with the defaults boolean
    for _ in 0..<stringTimeArr.count{defBoolArr.append(defBool)}

    // Map the array to global dictionary containing the Time in an array and default "false" value

    for i in 0..<stringTimeArr.count {
        recipeSettings.boolStirrSwitch[stringTimeArr[i]] = defBoolArr[i]
    }

    // Add the minutes to cell table
    cell.textLabel?.text = stringTimeArr[indexPath.row]
    return cell
}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}
}

正如您在我的代码中看到的，我确实将每个UI开关的状态保存在全局变量字典中。如何根据此代码解决UISwitch更改状态的问题？所有帮助表示赞赏。提前致谢

Answer 1

var switchState = [String : Bool]()

你的recipeSettings.boolStirrSwitch应该是这样的。
当您使用timeSelected作为numberOfRowsInSection时显示你的cell.textLabel，所以你不需要额外的stringTimeArr 为此。
您在cellForRowAt中所做的所有处理都将再次发生再次使用表格单元格以便设置数据在另一个表单中执行 function然后reload TableView。

问题的解决方案应该是这样的。

import UIKit

class StirrViewController: UIViewController, UITableViewDelegate, UITableViewDataSource{

//make tableView IBOutlet for reloading data
@IBOutlet weak var tableView: UITableView!

@IBOutlet weak var mylabel: UILabel!
var myString = String()

@IBAction func stirrBtn(_ sender: AnyObject) {
}

var timeSelected = String()
var selectedTimeArr = [String]()

override func viewDidLoad() {
    super.viewDidLoad()
    mylabel.text = myString
    self.timeSelected = myString
    self.setdefaultSwitchState()
}

//recipeSettings.boolStirrSwitch should be decleard like that
var switchState = [String : Bool]()

//setDeaultSwitchState
func setdefaultSwitchState(){
    if let timeSelected = Int(self.timeSelected){
        for value in 0..<timeSelected{
            switchState["\(value)"] = false
            //or
            //recipeSettings.boolStirrSwitch["\(value)"] = false
        }
    }
    self.tableView.reloadData()
}


@objc func switchChanged(_ sender : UISwitch!){
    print("table row switch Changed \(sender.tag)")
    print("The switch is \(sender.isOn ? "ON" : "OFF")")
    let kValue = (sender.tag + 1)
    let keyValue = String(kValue)
    if sender.isOn {
        switchState[keyValue] = true

    } else {
        switchState[keyValue] = false
    }
}

public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
    let stringNum = Int(self.timeSelected)
    recipeSettings.recipeTimeSet2 = stringNum!
    return(stringNum)!
}


public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
    var cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! UITableViewCell
    //here is programatically switch make to the table view
    let switchView = UISwitch(frame: .zero)
    switchView.setOn(false, animated: true)
    switchView.tag = indexPath.row // for detect which row switch Changed
    switchView.addTarget(self, action: #selector(self.switchChanged(_:)), for: .valueChanged)
    cell.accessoryView = switchView


    cell.textLabel?.text = "\(indexPath.row + 1)"
    if let switchState = switchState["\(indexPath.row)"] {
        if switchState{
            switchView.isOn = true
        }else{
            switchView.isOn = false
        }
    }else{
        switchView.isOn = false
    }

    return cell
}


func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}
}

Tableviewcell中的UISwitch状态在用户滚动时重置--Swift

1 个答案: