如何保留主题 ID，在 TableViewCell 中标记为已完成

Question

我想在 TableView 中跟踪已完成的主题列表

I have set delegate which confirms to tableView topic mark as completed

protocol TopicDetialVCDelegate: class {
func hasBeenCompletedTopic()

}

TableViewVC

func hasBeenCompletedTopic() {
    isPerformedDelegate = true
    if !completedTopicIdArray.contains(completedTopicId) {
        completedTopicIdArray.append(completedTopicId)
    }
    print("completed Topics \(completedTopicIdArray)")
    print("TopicVC: Completed Topics total: \(completedTopicIdArray.count)")
}

This is working, but i want to persist always mark as completed which already marked

Here is code of CellForRowAt

  if isPerformedDelegate {
        for _ in 0...completedTopicIdArray.count {
            if completedTopicIdArray.contains(filteredTopicArray[indexPath.row].id!) {
                cell.topicCompletedTickImageView.image = #imageLiteral(resourceName: "Tick")
            }
        }
    }

我想要什么

应该有一个数组来获取所有已完成的主题 idz，并且在应用程序的每个运行上检查单元格索引路径是否包含 topicID show Tick image

I can use UserDefaults like this

UserDefaults.standard.set(array, forkey: "abc")

但问题是数组将在应用程序的运行上再次重新初始化

like so in ViewWillDisappear

 override func viewWillDisappear(_ animated: Bool) {
    UserDefaults.standard.set(completedTopicIdArray, forKey: "completedTopics")
    UserDefaults.standard.synchronize()
}

accessing in ViewDidLoad

let topics = UserDefaults.standard.array(forKey: "completedTopics")
    print(topics as? [Int] ?? [Int]())

Answer 1

我已经用 CoreData 解决了这个问题，想分享一下

Declare empty array

 var completedTopicsIdPersistArray: [Int]    = [Int]()

CoreData Method for Creating

func persistIdIntoCoreData() {

    guard let appDelegate    = UIApplication.shared.delegate as? AppDelegate else { return }
    let managedObjectContext = appDelegate.persistentContainer.viewContext

    guard let entity = NSEntityDescription.entity(forEntityName: "ComTopicDB", in: managedObjectContext)
        else {
            print("Entity Not Found")
            return
    }

    let topicIdz = NSManagedObject(entity: entity, insertInto: managedObjectContext)
                topicIdz.setValue(completedTopicId, forKey: "topicId")

    do {
        try managedObjectContext.save()
    }
    catch let error as NSError {
        print("Unable to save into CoreData: \(error.userInfo)")
    }
}

CoreData Method for Retrieving

func retrieveIdFromCoreData() {

    guard let appDelegate    = UIApplication.shared.delegate as? AppDelegate else { return }
    let managedObjectContext = appDelegate.persistentContainer.viewContext
    let fetchRequest         = NSFetchRequest<NSManagedObject>(entityName: "ComTopicDB")

    do {
        let topicIdz = try managedObjectContext.fetch(fetchRequest)
        for id in topicIdz {

            let unwrapId = id.value(forKey: "topicId") as! Int
            if !completedTopicsIdPersistArray.contains(unwrapId) {
                completedTopicsIdPersistArray.append(unwrapId)
            }
        }
    }
    catch let error as NSError {
        print("Found issue during retrieve id from CoreData:\(error.userInfo)")
    }
}

Calling inside of delegate method, which confirms topic completed

func hasBeenCompletedTopic() {
    isPerformedDelegate = true
    if !completedTopicIdArray.contains(completedTopicId) {
        completedTopicIdArray.append(completedTopicId)
        persistIdIntoCoreData()
    }
    print("completed Topics \(completedTopicIdArray)")
    print("TopicVC: Completed Topics total: \(completedTopicIdArray.count)")
    retrieveIdFromCoreData()
}

and finally CellForRowAt Method

if completedTopicsIdPersistArray.contains(filteredTopicArray[indexPath.row].id!) {
        cell.topicCompletedTickImageView.image = #imageLiteral(resourceName: "Tick")
    }

Finally call inside ViewWillAppear, because it comes from topicDetailVC back

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    tableView.reloadData()
    retrieveIdFromCoreData()
}

现在所有主题都会显示勾号图标，标记为已完成，甚至终止并重新启动应用程序

如何保留主题 ID，在 TableViewCell 中标记为已完成

How to persist Topics ID, Which marked as completed in TableViewCell

uitableview

tableview

ios

swift