TableView创建重复的单元格

Question

当点击like按钮时，它应该会增加与之相关的单元格上的点赞数量，但我遇到了一个问题，它用更新后的点赞数创建了一个全新的单元格。我认为问题来自于im加载单元的方式。我认为我还需要添加函数remove()，以便在快照监听器生效后清除旧数据，但我不太确定。

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

这两个分支的功能完全相同。

在modified分支中，您必须在motivationThoughts中获取相应的对象，更新它并将其放回原处，而不是创建一个新对象。

就像这样

if diff.type == .modified {
    print("Modified data: \(diff.document.data())")
    let newdata = diff.document.data()

    let objectID = newdata["objectID"] as! String
    guard let dailymotivationIndex = motivationThoughts.firstIndex(where: {$0.dailyMotivationID == objectID}) else { return }

    var dailymotivation = self.motivationThoughts[dailymotivationIndex]
    let dailyMotivationNumberOfLikes = newdata["Number of likes in daily motivation post"] as! Int
    dailymotivation.RealmotivationNumberOfLikes = dailyMotivationNumberOfLikes
    self.motivationThoughts[dailymotivationIndex] = dailymotivation
}

我建议只重载modified分支中的行，而不是整个表视图。