ios - 在 UITableView 中选择行时不会更新变量

Question

我试图用在 UITableView 中选择的行号修改一个变量，这样我就可以从另一个 UIViewController 访问该变量，但是当我用 中的行号设置变量的值时>func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) 变量似乎没有改变。

我有一个带有 UITableView 的 View Controller ，我想要的是选择一行，然后，当我单击一个按钮时，会出现一个 Popoverview，我可以在其中参数化链接到我选择的行的内容。

这是我所做的:

import UIKit

class Settings: UIViewController , UITableViewDataSource, 
UITableViewDelegate{

    @IBOutlet weak var tableView: UITableView!
    var RowSelected = Int()

    let animals = ["Tap", "Double Tap", "Long press", "Swipe up", "Swipe down", "Swipe left", "Swipe right", "Zoom", "Unzoom"]

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell"/*Identifier*/, for: indexPath as IndexPath)
    cell.textLabel?.text = animals[indexPath.row]
    return cell
}

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

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

    RowSelected = indexPath.row
    print(RowSelected)
}

}

它在这里完美地打印了行，但是当我从另一个 ViewController 访问它时它总是等于 0。

import UIKit

class GestureConfiguration: UIViewController, 
UICollectionViewDataSource, UICollectionViewDelegate, UITableViewDataSource, UITableViewDelegate {

@IBOutlet weak var actionSelected: UILabel!

let reuseIdentifier = "cell" // also enter this string as the cell identifier in the storyboard
var items = ["1", "2", "3", "4", "5"]
var index : Int = 1

var scVC = Settings()

let gestes = ["Tap", "Double Tap", "Long press", "Swipe up", "Swipe down", "Swipe left", "Swipe right", "Zoom", "Unzoom"]

@IBOutlet weak var tableView: UITableView!

func numberOfSections(in collectionView: UICollectionView) -> Int {
    return 9
}

// tell the collection view how many cells to make
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

    return self.items.count
}

// make a cell for each cell index path
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {


    collectionView.allowsMultipleSelection = true

    // get a reference to our storyboard cell
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath as IndexPath) as! MyCollectionViewCell

    // Use the outlet in our custom class to get a reference to the UILabel in the cell
    cell.myLabel.text = self.items[indexPath.item]
    cell.backgroundColor = UIColor(red:0.13, green:0.37, blue:0.58, alpha:0.7)
    cell.layer.borderColor = UIColor.black.cgColor
    cell.layer.borderWidth = 1

    return cell
}


func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    // handle tap events
    let cell = collectionView.cellForItem(at: indexPath)
    print("You selected cell #\(indexPath.item + 1) section \(indexPath.section + 1)")
    cell?.backgroundColor = UIColor(red:0.08, green:0.28, blue:0.45, alpha:1.0)
    ///////// HERE \\\\\\\\\\
    actionSelected.text = String(scVC.RowSelected)
    print(scVC.RowSelected)
    // Always print 0, same for the label.
}

func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
    // handle tap events
    let cell = collectionView.cellForItem(at: indexPath)
    print("You unselected cell #\(indexPath.item + 1) section \(indexPath.section + 1)")
    cell?.backgroundColor = UIColor(red:0.13, green:0.37, blue:0.58, alpha:0.7)
}

我错过了什么？当我将一个值硬编码到 RowSelected(如 99)时，我能够在我的第二个 ViewController 中看到 99。

感谢您的帮助。

Akhilrajtr 的编辑:

class Settings: UIViewController , UITableViewDataSource, UITableViewDelegate{

@IBOutlet weak var tableView: UITableView!
var RowSelected = Int()

let animals = ["Tap", "Double Tap", "Long press", "Swipe up", "Swipe down", "Swipe left", "Swipe right", "Zoom", "Unzoom"]

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell"/*Identifier*/, for: indexPath as IndexPath)
    cell.textLabel?.text = animals[indexPath.row]
    return cell
}

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

//Not overriding any function, 
Override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if (segue.identifier == "toPopover") {
        var secondViewContr =  segue.destination as! GestureConfiguration
        secondViewContr.scVC = self
    }
}
}

并且:

class GestureConfiguration: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UITableViewDataSource, UITableViewDelegate {

@IBOutlet weak var actionSelected: UILabel!

var scVC = Settings()

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    // handle tap events
    let cell = collectionView.cellForItem(at: indexPath)
    print("You selected cell #\(indexPath.item + 1) section \(indexPath.section + 1)")
    cell?.backgroundColor = UIColor(red:0.08, green:0.28, blue:0.45, alpha:1.0)

    actionSelected.text = String(scVC.RowSelected)
    print(scVC.RowSelected)
}

Answer 1

在 GestureConfiguration 中创建一个 Settings class 变量，然后在 tableViewDelegate 函数中访问它。

在 Settings 类中覆盖函数 prepareforsegue as

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        if let gestuedistination = segue.destination as? GestureConfiguration {
            gestuedistination.settings = self
        }
}

在GestureConfiguration类中声明

@IBOutlet weak var actionSelected: UILabel!
var settings:Settings?

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        // handle tap events
        let cell = collectionView.cellForItem(at: indexPath)
        print("You selected cell #\(indexPath.item + 1) section \(indexPath.section + 1)")
        cell?.backgroundColor = UIColor(red:0.08, green:0.28, blue:0.45, alpha:1.0)
        actionSelected.text = String(settings!.RowSelected)
        print(settings!.RowSelected)
}