Question

应用程序结构：

我有一个Collection View Controller，这是我创建的徽标测验游戏的一个级别。如果用户猜到徽标，我会将其存储在UserDefaults中并在Collection View中检索，这会将复选标记图像放到单元格上。

问题：

一切正常，但当用户从测验视图返回Collection View Controller时，检查标记未显示。但是，如果我返回级别菜单然后打开Collection View Controller，则复选标记会正确显示。我尝试使用dispatch方法解决此问题，但它没有帮助！我也尝试了CollectionView.reloadData方法，但仍然没有任何反应！

我的代码：

import UIKit


class CollectionViewController: UICollectionViewController {

    var array = ["Youtube.jpeg","Facebook.svg.png","Google.png","Burger King.png"]
    var tappedImage = String()
    var associatedString = ""
    var expectedAnswer = ""
    let defaults = UserDefaults.standard
    var indexx = 0
    var checked: Bool = false

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }



    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return array.count
    }

    //performSegueWithIdentifier("ShowColor", sender: sender)

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
        let ImageView = cell.viewWithTag(1) as! UIImageView
        ImageView.image = UIImage(named: array[indexPath.row])
        let button = cell.viewWithTag(2) as! UIButton
        button.tag = indexPath.row
        button.addTarget(self, action: #selector(sendInformation), for: .touchUpInside)
        let checkImage = cell.viewWithTag(3) as! UIImageView
        var name = array[button.tag]
        if let dotRange = name.range(of: ".") {
            name.removeSubrange(dotRange.lowerBound..<name.endIndex)
            expectedAnswer = name
        }

         if defaults.value(forKey: "\(expectedAnswer)") != nil{
         let isChecked = defaults.value(forKey: "\(expectedAnswer)") as! Bool
         if isChecked == true{
            checkImage.image = UIImage(named: "checkmark1.png")
         }
         }



        return cell
    }
    override func prepare(for segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "quizSegue" {
            if let quizViewController = segue.destination as? QuizVC {
                quizViewController.image = self.tappedImage
                quizViewController.expectedAnswer = self.expectedAnswer
            }
        }
    }

    func sendInformation(_ sender: UIButton){
        tappedImage = array[sender.tag]
        var name = array[sender.tag]
        if let dotRange = name.range(of: ".") {
            name.removeSubrange(dotRange.lowerBound..<name.endIndex)
            expectedAnswer = name
            print(expectedAnswer)
        }
        self.performSegue(withIdentifier: "quizSegue", sender: nil)
    }

    @IBAction func unwindToCollectionView(segue: UIStoryboardSegue){

    }

注意：您的答案可以在swift 2中，我可以轻松翻译它！我使用了swift 3。非常感谢任何帮助！

Answer 1

经过大量谷歌搜索，我终于解决了这个问题。在Collection View Controller：

 override func viewWillAppear(_ animated: Bool) {
        let parent = self.view.superview
        self.view.removeFromSuperview()
        self.view = nil
        // unloads the entire view
        parent?.addSubview(self.view)
        // reloads the view
    }

collectionView.reloadData

无法正常工作，因为我有一个重新加载的按钮导致：

EXC_BAD指令

我刚强迫视图重新加载。我不会删除此问题，因为其他人可能会觉得它很有用......源代码来自reload/refresh subViews - setNeedsDisplay doesnt work。

集合视图更新问题 - Swift

应用程序结构：

问题：

我的代码：

1 个答案: