Question

我正在使用包含UITableViewCell的{{1}}原型，并将该原型用于UIPickerView中4个不同PickerView的4个不同单元格。我使用以下代码将单元格提供给tableView tableView并将每个选择器设置为不同的实例变量，以便稍后区分选择器（因为相同的(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath)实例是委托/数据源所有这些，例如）。

但是，在运行代码时，所有4个实例变量最终都指向同一个UITableViewController。如何确保它使用4个不同的UIPickerView代替？

UIPickerViews

Answer 1

而不是使用POSITION_NONE尝试这样的事情。像这样更改tag的{{1}}

didSelectRow

在您的文件中添加PickerViewDelegate数组，并按照以下方式在func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) { let cell = imageView.superview?.superview as! UITableViewCell //You have to use as may super as your UITableViewCell hierarchy let indexPath = self.tabelView.indexPathForCell(cell) self.pickerSelectedIndexArr[indexpath.row] = row }中分配

pickerSelectedIndexArr

现在，您可以随时轻松获取所有选择器选择的值希望这会对你有所帮助。

Answer 2

var dict: [Int, UIPickerView]

...

if dict[indexPath.row] == nil {
    // Create UIPickerView and assign it to dict[indexPath.row].
}

Answer 3

由于此问题标有Objective C，我将在OBJC中给出答案。

以下是您可以执行的操作，以处理可重用单元格中的控件，

解决此类问题的提示when you have controls in UICollectionViewCell or UITableViewCell, give tag to your controls depending upon your indexPath。

使用collectionViewCell给出示例，您可以使用tableViewCell进行操作案例1：如果CollectionView是截面的，那么你的标签就像[0] [0]，[1] [0] ......在这种情况下做类似的事情，

collectionViewCell.picker.tag = [[NSString stringWithFormat:@"%ld%ld",(long)indexPath.section,(long)indexPath.item] intValue]; // If it is sectional collection view

案例2：如果集合视图是非截面的，请执行以下操作，

collectionViewCell.picker.tag = [[NSString stringWithFormat:@"%ld",(long)indexPath.item] intValue]; // If it is non-sectional collection view

希望这可以解决您的问题或让您相应地进行管理。如果你的单元格中有多个控件，那么只需给出indexPath.item + 1 + 2 ...

等标签

Answer 4

我同意Nirav的意见，您应该使用该单元格来确定相关单元格的NSIndexPath。

就个人而言，我将单元格子类化为选择器的数据源和委托，并让它对选择器负责。这完全消除了关于哪个拾取器与哪个单元相关联的任何混淆。但是我有一个协议，当用户从选择器中选择一个值并且视图控制器可以更新模型时，单元可以通过该协议通知视图控制器。

例如，考虑这个UITableViewCell子类：

//  CustomCell.swift

import UIKit

/// Protocol that the view controller will conform to in order to receive updates
/// from the cell regarding which row in the picker was picked.
///
/// - note: This is a `class` protocol so that I can use `weak` reference.

protocol CustomCellDelegate: class {
    func cell(customCell: CustomCell, pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
}

/// Custom cell subclass, which is the picker's data source and delegate

class CustomCell: UITableViewCell, UIPickerViewDataSource, UIPickerViewDelegate {

    /// The delegate who we will inform of any picker changes.
    ///
    /// This is weak to avoid strong reference cycle.

    weak var delegate: CustomCellDelegate?

    /// The array of values to be shown in the picker.
    ///
    /// If the `values` changes, this reloads the picker view.

    var values: [String]? {
        didSet {
            pickerView.reloadComponent(0)
        }
    }

    /// The outlet to the picker in the cell.

    @IBOutlet weak var pickerView: UIPickerView!

    // MARK: UIPickerViewDataSource

    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return values?.count ?? 0
    }

    // MARK: UIPickerViewDelegate

    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return values?[row] ?? ""
    }

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        delegate?.cell(self, pickerView: pickerView, didSelectRow: row, inComponent: component)
    }
}

然后是视图控制器：

//  ViewController.swift

import UIKit

class ViewController: UITableViewController, CustomCellDelegate {

    // an array of arrays of acceptable values

    let troupes = [
        ["Mo", "Larry", "Curly"],
        ["Abbott", "Costello"],
        ["Groucho", "Harpo", "Zeppo", "Chico", "Gummo"],
        ["Laurel", "Hardy"],
        ["Graham Chapman", "John Cleese", "Terry Gilliam", "Eric Idle", "Terry Jones", "Michael Palin"]
    ]

    /// An array that indicates which is item is selected for each table view cell

    var selectedItemForRow: [Int]!

    override func viewDidLoad() {
        super.viewDidLoad()

        selectedItemForRow = troupes.map { _ in return 0 }    // initialize the `selectedItemForRow` array with zeros

        // Whatever further initialization of the view controller goes here.
    }

    // MARK: UITableViewDataSource

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return troupes.count
    }

    // Populate cell, setting delegate, list of acceptable values, and currently selected value.

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("CustomCell", forIndexPath: indexPath) as! CustomCell
        cell.delegate = self
        cell.values = troupes[indexPath.row]
        cell.pickerView.selectRow(selectedItemForRow[indexPath.row], inComponent: 0, animated: false)
        return cell
    }

    // MARK: CustomCellDelegate

    // When the cell tells us that the user changed the selected row, let's update our model accordingly.

    func cell(customCell: CustomCell, pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        if let indexPath = tableView.indexPathForCell(customCell) {
            selectedItemForRow[indexPath.row] = row
        }
    }

}

如何在原型UITableViewCells

4 个答案: