在 table 视图单元格中使用步进器 - 但返回到 VC 的数据未正确更新

Question

我正在尝试创建一个配置屏幕，以便用户可以设置他或她想要进行的锻炼次数。我设法将表格视图添加到空白视图控制器，但存在一些风格限制 - 例如根据单元格数量展开和折叠表格视图。

所以我想我会在 tableviewcontroller 中设置屏幕。现在一切顺利，直到我到达我想要 section 0、cell 1 中的 Stepper 来增加和减少 [= 中的行数的地步=18=]。它的工作范围是数据数组（workouts[]）用最新值（在 cellForRowAt:indexPath 方法中）更新视图控制器，而视图控制器又用（假定的）最新值更新 numberOfRowsInSection workouts.count.

然而，事实证明 workouts.count 保存了步进器最后更新数组之前的计数。

现在，我已经尝试了一些解决方法，但我仍然无法使 numberOfRowsInSection 方法正确更新 - 在我看来，Workouts 数组未在视图控制器中更新最新值，而不是之前的设定值。

这是我的视图控制器：

class AViewController: UITableViewController {

//MARK: Properties
@IBOutlet weak var aTableView: UITableView!

var sections: [String] = ["", "Set Up Circuits"]
var workouts: [Exercise] = []

//MARK: Initialisation
override func viewDidLoad() {
    super.viewDidLoad()
    workouts = [Exercise(name: "Circuit 1", timeMinutes: 2)]
    self.tableView.delegate = self
    self.tableView.dataSource = self
}

//MARK: Table Config
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return self.sections[section]
}

override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
    switch section {
    case 0:
        return 0.1
    default:
        return 32.0
    }
}

override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    switch indexPath.section {
    case 0:
        return 60
    default:
        return 44
    }
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    var numberOfRowsInSection: Int = 0

    switch section {
    case 0:
        numberOfRowsInSection = 1
    default:
        numberOfRowsInSection = workouts.count
        //numberOfRowsInSection = 1
    }
    print(numberOfRowsInSection, "number of rows in section", section)
    return numberOfRowsInSection
}

//MARK: Table Protocols
override func numberOfSections(in tableView: UITableView) -> Int {
    return sections.count
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    switch indexPath.section {

    //Setting layout for circuit number config
    case 0:
        let cell = aTableView.dequeueReusableCell(withIdentifier: "ACircuitTableViewCell") as! ACircuitTableViewCell
        cell.tableView = self.aTableView
        self.workouts = cell.workouts
        print(workouts.count, " VC workouts array count")
        return cell

    //Setting layout for circuit cells
    default:
        let cell = aTableView.dequeueReusableCell(withIdentifier: "ATableViewCell") as! ATableViewCell
        cell.aLabel.text = workouts[indexPath.row].getName()
        cell.aDetail.text = "Tap here to configure"
        return cell

    }
}

这是我的 ACircuitTableViewCell：

class ACircuitTableViewCell: UITableViewCell {

//MARK: Properties
@IBOutlet weak var circuitNumber: UILabel!
@IBOutlet weak var circuitLabel: UILabel!
@IBOutlet weak var circStepper: UIStepper!


var tableView: UITableView!
// var updateCallback : ((_ updateList: Bool)-> Void)?

//var exercises: [Exercise]?
var anArray: [Exercise] = []
var workouts: [Exercise] = [Exercise(name: "Circuit 1", timeMinutes: 2)]

var workoutsCount: Int = 1
var indexPath: NSIndexPath = NSIndexPath(row: 0, section: 1)
//MARK: Original Functions
override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code

    circuitNumber.text = String(workouts.count)
}

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)
}

@IBAction func valueChanged(_ sender: AnyObject) {
    print("Method .valueChanged activated")

    //Update circuitNumber label
    circuitNumber.text = String(Int(circStepper.value))

    //View pre-array-update status of variables
    print(workouts.count, "anArray before appending")
    print(circStepper.value, "stepper value before appending")
    print(circuitNumber.text, "circuitNumber")

    //Update workouts array
    if workouts.count < Int(circStepper.value) {
        workouts.append(Exercise(name: "Circuit \(Int(circStepper.value))", timeMinutes: 2))
        print(workouts.count, "after appending")

        tableView.reloadData()

       print(workouts.count, "new workout.count")
    }


    print(workouts.count, "workouts.count")
    print("Method .valueChanged completed")

}

这是从应用程序加载到在步进器 + 按钮上轻按三下到控制台的输出。

1 number of rows in section 1
1 number of rows in section 0
1 number of rows in section 1
1 number of rows in section 0
1 number of rows in section 1
1 number of rows in section 0
1  VC workouts array count
Method .valueChanged activated
1 anArray before appending
2.0 stepper value before appending
Optional("2") circuitNumber
2 after appending
1 number of rows in section 1
1 number of rows in section 0
2 new workout.count
2 workouts.count
Method .valueChanged completed
2  VC workouts array count
Method .valueChanged activated
2 anArray before appending
3.0 stepper value before appending
Optional("3") circuitNumber
3 after appending
2 number of rows in section 1
1 number of rows in section 0
3 new workout.count
3 workouts.count
Method .valueChanged completed
3  VC workouts array count
Method .valueChanged activated
3 anArray before appending
4.0 stepper value before appending
Optional("4") circuitNumber
4 after appending
3 number of rows in section 1
1 number of rows in section 0
4 new workout.count
4 workouts.count
Method .valueChanged completed
4  VC workouts array count
Method .valueChanged activated
4 anArray before appending
5.0 stepper value before appending
Optional("5") circuitNumber
5 after appending
4 number of rows in section 1
1 number of rows in section 0
5 new workout.count
5 workouts.count
Method .valueChanged completed
5  VC workouts array count

Answer 1

您应该在控制器中处理步进器回调并在那里更改 viewController 的数据源。

在视图控制器中处理单元格事件的最常见方法是使用委托，就像我在此处描述的那样：
或者，您可以在 cellForRow 方法中添加带有 self 目标的操作：

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell") as! TableViewCell
    cell.stepper?.tag = indexPath.row
    cell.stepper?.addTarget(self, action: #selector(stepperValueChanged(_:)), for: .valueChanged)
    return cell
}

func stepperValueChanged(_ stepper: UIStepper) {
    //use stepper.tag as index to fetch an object from your dataSource
    let workout = dataSource[stepper.tag]
}

在 table 视图单元格中使用步进器 - 但返回到 VC 的数据未正确更新

Using a stepper in a table view cell - but the data returning to the VC is not updating correctly

ios

arrays

uitableview

uistepper