Question

我正在创建前十名单。我需要某些项的值来获得一个值，并且每当某个人同意时，该值就会增加。它目前没有更新，但试图添加相同的值并立即消失。这是我的Firebase堆栈....

TopVideos-->
 yWfsla_Uh80-->
   Value: 1
   description: "Download on iTunes : KOR https://itunes.apple.c..."
   imageString: "https://i.ytimg.com/vi/yWfsla_Uh80/default.jpg"
   rank: 1
   title: "EXO_CALL ME BABY_Music Video"
   user: "6ef370d4-a1bd-48ce-9ae0-93d2e20f3bc8"
   videoID: "yWfsla_Uh80"

我想增加＆＃34;价值＆＃34;孩子/节点，但它没有发生。这是我的代码....

topVideoRef.childByAppendingPath("Value").runTransactionBlock({
                (currentData:FMutableData!) in
                var value = currentData.value as? Int
                if value == nil  {
                    value = 0
                }
                currentData.value = value! + 1
                return FTransactionResult.successWithValue(currentData)
            })

我按照Firebase指南写了这封信，但我可能会遗漏一些东西。顺便说一下......如果你知道答案，请包括如何减少价值。谢谢。

*更新*

我正在创建视频参考.....

vidRank = Int(self.rankValue.text!)!
let vidArray = ["user" : self.ref.authData.uid, "videoID": self.videoId, "rank": self.vidRank, "title": self.vidTitleText, "description": self.vidDescription, "imageString": self.vidIMG]
let topVideoRef = self.ref.childByAppendingPath("TopVideos/\(self.videoId)")
topVideoRef.setValue(vidArray)

Answer 1

我通过用文本替换字段来修改代码，然后创建了两个函数，链接到窗口上的两个按钮

然后运行代码，它似乎工作。

func clickedButton1() {

    print("Button1Action")

    let myRootRef = Firebase(url:"https://your-app.firebaseio.com")

    let vidArray = ["user" : "some user id",
        "videoID": "some video id",
        "rank": "some rank",
        "title": "a title",
        "description": "a description",
        "imageString": "an image"]


    let topVideoRef = myRootRef.childByAppendingPath("TopVideos/\("vid_id_0")")
    topVideoRef.setValue(vidArray)

}

和第二个功能

func clickedButton2() {

    print("Button2Action")

    let myRootRef = Firebase(url:"https://your-app.firebaseio.com")

    let topVideoRef = myRootRef.childByAppendingPath("TopVideos/\("vid_id_0")")

    topVideoRef.childByAppendingPath("Value").runTransactionBlock({
        (currentData:FMutableData!) in
        var value = currentData.value as? Int
        if value == nil  {
            value = 0
        }
        currentData.value = value! + 1
        return FTransactionResult.successWithValue(currentData)
    })

}

单击按钮1时，将写出初始数据。

每次单击按钮2时，“值”节点将增加1.

我猜你要么在某个时候覆盖整个节点，要么在你退出应用程序时将一个onDisconnect附加到Value上删除它。

或者......它被设置为nil，这将导致你所看到的。它会有一个价值然后突然消失。

Answer 2

谢谢@Jay的回答。它更好地理解了Firebase数据;检索和存储。我被困了一段时间，因为我得到了我的按钮添加然后更新，但它被连续循环捕获。一旦我使用observeSingleEventofType，它就会聚集在一起。这是我完成的代码，我最初为用户保存视频，然后检查视频是否为＃1视频，并从那里保存或更新...

  @IBAction func finalSaveBTN(sender: AnyObject)
    {
        vidRank = Int(self.rankValue.text!)!
        let vidArray = ["user" : self.ref.authData.uid, "videoID": self.videoId, "rank": self.vidRank, "title": self.vidTitleText, "description": self.vidDescription, "imageString": self.vidIMG]
        let videoRef = self.ref.childByAppendingPath("UserVideo/\(self.ref.authData.uid)/Vid\(vidRank)")
        videoRef.setValue(vidArray)

        if self.vidRank == 1
        {
            let findTopRef = self.ref.childByAppendingPath("TopVideos/\(self.videoId)")
            findTopRef.queryLimitedToFirst(1)
                .observeSingleEventOfType(.Value, withBlock: { snapshot in
                    if snapshot.value is NSNull
                    {
                        print("Save")
                        self.clickedButton1()
                    }
                    else
                    {
                        print("Updated")
                        self.clickedButton2()
                    }
                })
        }
    }

    func clickedButton1()
    {
        print("Button1Action")
        let vidArray = ["Value" : 1, "videoID": self.videoId, "title": self.vidTitleText, "description": self.vidDescription, "imageString": self.vidIMG]
        let topVideoRef = self.ref.childByAppendingPath("TopVideos/\(self.videoId)")
        topVideoRef.setValue(vidArray)
    }

    func clickedButton2()
    {
        print("Button2Action")
        let topVideoRef = self.ref.childByAppendingPath("TopVideos/\(self.videoId)")
        topVideoRef.childByAppendingPath("Value").runTransactionBlock({
            (currentData:FMutableData!) in
            var value = currentData.value as? Int
            if value == nil  {
                value = 0
            }
            currentData.value = value! + 1
            return FTransactionResult.successWithValue(currentData)
        })
    }

如果出现问题，请发表评论。顺便说一句，如果＃1 Vid已经存在，我仍然需要降低价值。

Firebase值不随Swift增加？

2 个答案: