ios - tableViewCell 不更新数据，因为它只显示空白

问题描述

我正在尝试创建一个表格视图，该表格视图使用从用户接收输入的文本字段显示在另一个视图控制器中生成的数据，然后我使用核心数据保存这些输入，然后我想将它们加载到 tableView 单元格中，除非它们不加载在所有的细胞上。

我真的被困住了，我不知道该尝试什么

这是第一个包含 tableView 的 VC

    import UIKit
    import CoreData

let appDelegate = UIApplication.shared.delegate as? AppDelegate

class FriendsVC: UIViewController, UITableViewDelegate, UITableViewDataSource {

    @IBOutlet weak var tableView: UITableView!

    var friends : [Friend] = []


    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.reloadData()
        tableView.delegate = self
        tableView.dataSource = self
    }
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        self.tableView.reloadData()
        if friends.count >= 1{
            let endIndex = IndexPath(row: friends.count - 1, section: 0)
            tableView.scrollToRow(at: endIndex, at: .bottom, animated: false)
        }
    }
    @IBAction func addFriendsButtonWasPressed(_ sender: Any) {
        performSegue(withIdentifier: "toCreateFriends", sender: self)
    }


    func fetchCoreDataObjects(){
        self.fetch { (complete) in
            if complete{
                if friends.count >= 1 {
                    tableView.isHidden = false
                }else {
                    tableView.isHidden = true
                }
            }
        }
    }
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

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

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        guard let cell = tableView.dequeueReusableCell(withIdentifier: "FC") as? FriendCell  else{
            return UITableViewCell()
    }
        let friend = friends[indexPath.row]
        cell.configureCell(friend: friend)
        return cell
    }
    func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        return true
    }
    func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCell.EditingStyle {
        return .none
    }
    func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
        let deleteAction = UITableViewRowAction(style: .destructive, title: "Delete") { (rowAction , indexPath) in
            self.removeFriend(atIndexPat: indexPath)
            self.fetchCoreDataObjects()
            tableView.deleteRows(at: [indexPath], with: .automatic)

        }

        deleteAction.backgroundColor = #colorLiteral(red: 0.8078431487, green: 0.02745098062, blue: 0.3333333433, alpha: 1)
        return [deleteAction]
    }
}
extension FriendsVC {

    func fetch(completion : (_ complete : Bool)->()){
        guard let managedContext = appDelegate?.persistentContainer.viewContext else{return}
        let fetchRequest = NSFetchRequest<Friend>(entityName: "Friend")
        do{
            friends = try managedContext.fetch(fetchRequest)
            completion(true)
        } catch{
            debugPrint("Couldn't fetch\(error.localizedDescription)")
            completion(false)
        }
}

    func removeFriend(atIndexPat indexPath: IndexPath){
        guard let managedContext = appDelegate?.persistentContainer.viewContext else {return}
        managedContext.delete(friends[indexPath.row])
        do {
            try managedContext.save()
        } catch{
            debugPrint("Couldn't remove\(error.localizedDescription)")
        }

    }
}

-------------------------------------------------- ----------------------这是用户应该创建新朋友数据的另一个VC

    import UIKit
import CoreData

class CreateFriendsVC: UIViewController, UITableViewDelegate {

    @IBOutlet weak var nameLbl: UITextField!
    @IBOutlet weak var ageLbl: UITextField!
    @IBOutlet weak var genderLbl: UITextField!
    @IBOutlet weak var createBtn: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()
        createBtn.bindToKeyboard()
        let tap = UITapGestureRecognizer(target: self, action: #selector(CreateFriendsVC.handleTap))
        let pan = UIPanGestureRecognizer(target: self, action: #selector(CreateFriendsVC.handleTap))
        view.addGestureRecognizer(tap)
        view.addGestureRecognizer(pan)

    }
    @objc func handleTap(){
        view.endEditing(true)
    }

    @IBAction func createBtnPressed(_ sender: Any) {
        if nameLbl.text != "" && ageLbl.text != "" && genderLbl.text != "" {
            self.save { (complete) in
                if complete{
                    dismiss(animated: true, completion: nil)

                }
            }
        }

        dismiss(animated: true, completion: nil)
    }

    func save(completion : (_ finished : Bool)->()){
        guard let managedContext = appDelegate?.persistentContainer.viewContext else{return}
        let friend = Friend(context: managedContext)
        friend.age = ageLbl.text!
        friend.gender = genderLbl.text!
        friend.name = nameLbl.text!
        do{
            try managedContext.save()
            completion(true)
            print("Save success")
            print(friend.age!)
        } catch{
            debugPrint("Couldn't Save: \(error.localizedDescription)")
            completion(false)
        }
    }

}

==================================================== ======================这是自定义单元生成器

    import UIKit

class FriendCell: UITableViewCell {
    @IBOutlet weak var nameTxtLbl: UILabel!
    @IBOutlet weak var ageTxtLbl: UILabel!
    @IBOutlet weak var genderTxtLbl: UILabel!

    override func awakeFromNib() {
        super.awakeFromNib()
        // Initialization code
    }

    func configureCell(friend : Friend){
        self.nameTxtLbl.text = friend.name
        self.ageTxtLbl.text = friend.age
        self.genderTxtLbl.text = friend.gender

    }

}

预期的结果应该是一个表格视图，其中的单元格显示所有用户输入的数据。实际结果是一个空的表格视图单元格

标签： iosswift

ios - tableViewCell 不更新数据，因为它只显示空白

问题描述

解决方案

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