当快照侦听器生效时，Tableview Like按钮会进行复制

Question

所以基本上，当点击点赞按钮时，它假设会更改表视图中的点赞数量，但实际发生的是，它在表视图数组的底部创建了一个重复的单元格，而它的新点赞数量使我做错了什么，但我不确定如果有更好的方法可以做到这一点，我会感谢向我展示它

import UIKit
import Firebase
class motivationviewcontroller : UIViewController,UITableViewDataSource ,UITableViewDelegate{

var motivationThoughts = [motivationDailyModel]()
var Mous = motivationDailyModel()
var tableview : UITableView!
override func viewDidLoad() {
print("the user logged in is ( String(describing: Auth.auth().currentUser?.email))")
tableview =  UITableView(frame: view.bounds, style: .plain)
tableview.backgroundColor = UIColor.white
view.addSubview(tableview)

var layoutGuide : UILayoutGuide!
layoutGuide = view.safeAreaLayoutGuide
let cellNib = UINib(nibName: "dailyMotivationTableViewCell", bundle: nil)
tableview.register(cellNib, forCellReuseIdentifier: "DailyThoughtCELL")
tableview.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
tableview.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
tableview.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
tableview.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true

tableview.dataSource = self
tableview.delegate = self

loaddailymotivation()
//listener()
self.tableview.reloadData()

}
override func viewDidAppear(_ animated: Bool) {
//loaddailymotivation()
self.tableview.reloadData()

}

//======================================================================

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
motivationThoughts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "DailyThoughtCELL", for: indexPath) as? dailyMotivationTableViewCell
cell!.generateCellsforDailymotivation(_MotivationdataMODEL: self.motivationThoughts[indexPath.row])
return cell!
}

func loaddailymotivation() {
FirebaseReferece(.MotivationDAILY).addSnapshotListener { querySnapshot, error in
guard let snapshot = querySnapshot else {
print("Error fetching snapshots: (error!)")
return
}
snapshot.documentChanges.forEach { diff in
if (diff.type == .added) { // this line means if the chage that happened in the document was equal to added something
let data = diff.document.data()
print("we have(snapshot.documents.count) documents in this array")
let dailyMotivationID = data["objectID"] as! String
let dailymotivationTitle = data["Motivation title"] as! String //calls the data thats heald inside of motivation title in firebase
let dailyMotivationScripture = data["daily motivation scripture"] as! String //calls the data thats heald inside of Motivation script in firebase
let dailyMotivationNumberOfLikes = data["Number of likes in daily motivation post"]as! Int

let MdataModel = motivationDailyModel(RealMotivationID: dailyMotivationID, RealmotivationTitle: dailymotivationTitle, RealmotivationScrip: dailyMotivationScripture, RealmotivationNumberOfLikes: dailyMotivationNumberOfLikes)
self.motivationThoughts.append(MdataModel)
}
//===== //=====
if (diff.type == .modified) {
print("Modified data: (diff.document.data())")
let newdata = diff.document.data()
let dailyMotivationID = newdata["objectID"] as! String
let dailymotivationTitle = newdata["Motivation title"] as! String //calls the data thats heald inside of motivation title in firebase
let dailyMotivationScripture = newdata["daily motivation scripture"] as! String //calls the data thats heald inside of Motivation script in firebase
let dailyMotivationNumberOfLikes = newdata["Number of likes in daily motivation post"]as! Int

let MdataModel = motivationDailyModel(RealMotivationID: dailyMotivationID, RealmotivationTitle: dailymotivationTitle, RealmotivationScrip: dailyMotivationScripture, RealmotivationNumberOfLikes: dailyMotivationNumberOfLikes)

self.motivationThoughts.append(MdataModel)
//  here you will receive if any change happens in your data add it to your array as you want
}
DispatchQueue.main.async {
self.tableview.reloadData()
}
}
}
}

Answer 1

我不知道loaddailymotivation()是否在viewDidLoad之后再次调用，但在该方法中，您正在执行self.motivationThoughts.append(MdataModel)，它应该与您所说的完全一样。

我认为您需要一个方法来标识数组中需要修改的项，并替换/修改它。如果你添加了一个新对象，你的表中就多了一个元素