Swift Firebase - 尝试在函数中检索多组数据以计算条目数-Java 学习之路

我在一个函数中尝试从Firebase检索两组数据时遇到问题 . 在检索之后，此检索的结果将用于更新进度条（否则为'zero'值），因此此'progress bar'函数也包含在Firebase函数中 . 为了进一步澄清，我试图从Firebase Db获取'user-posts'和'user-plans'的条目数： -
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函数的代码看起来像这样（然后我会让你知道问题是什么！）： -

func firebaseRetrieve() {

    guard let uid = Auth.auth().currentUser?.uid else {return}

    let planRef = DB_BASE.child("user-plan").child(uid)
    planRef.observeSingleEvent(of: .value, with: { (snapshot) in
        for child in snapshot.children {
            let snap = child as! DataSnapshot
            let key = snap.key
            self.totalPlans.append(key)
            self.planCount = Double(self.totalPlans.count)

            let postRef = DB_BASE.child("user-posts").child(uid)
            postRef.observeSingleEvent(of: .value, with: { (snapshot) in
                for child in snapshot.children {
                    let snaps = child as! DataSnapshot
                    let keys = snaps.key
                    self.totalPosts.append(keys)
                    self.postCount = Double(self.totalPosts.count)

                    self.fraction = self.postCount / self.planCount

                    //THIS IS WHERE I INPUT ANOTHER FUNCTION TO PASS THE VALUE OF 'FRACTION' INTO, THAT THNE DETERMINES THE PROGRESS BAR
                }
            })
        }
    })

问题：“用户计划”的当前计数为18.当前的“用户帖子”数为14.因此该分数应该等于0.77（78％） . 但是，“用户帖子”的数量似乎重复了18次，所以计数是252（即14 * 18）!!在过去的3天里，我尝试了各种修复方法，但结果总是相同的 . 任何想法都很受欢迎，并会阻止我发誓妻子......

1 回答

您可以使用snapshot.childrenCount来获取快照子项的计数，并且您需要在循环外部移动计算

结帐此代码

func firebaseRetrieve() 
{

    guard let uid = Auth.auth().currentUser?.uid else {return}

    let planRef = DB_BASE.child("user-plan").child(uid)
    planRef.observeSingleEvent(of: .value, with: 
    { 
        (snapshot) in

        self.planCount = snapshot.childrenCount;
        for child in snapshot.children 
        {
            let snap = child as! DataSnapshot
            let key = snap.key
            self.totalPlans.append(key)
        }


        let postRef = DB_BASE.child("user-posts").child(uid)
        postRef.observeSingleEvent(of: .value, with: 
        { 
            (snapshot) in

            self.postCount = snapshot.childrenCount;
            for child in snapshot.children 
            {
                let snaps = child as! DataSnapshot
                let keys = snaps.key
                self.totalPosts.append(keys)
            }

            self.fraction = self.postCount / self.planCount;
            print("fraction = \(self.fraction)")

        })

    });

}

回复于 2024-05-06T15:12:48+08:00

Swift Firebase - 尝试在函数中检索多组数据以计算条目数

1 回答

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