我正在试图从Firebase检索信息。我可以用JSON获取快照,但在访问快照和保存应用程序中的值时遇到问题。
代码如下所示:

self.ref.child("users").child(userFound.userRef!).child("currentGame").observeSingleEvent(of: .value, with: { (snapshot) in

                print(snapshot)

                if let snapDict = snapshot.value as? [String:AnyObject] {


                    for each in snapDict {
                        self.theApp.currentGameIDKey = String(each.key)
                        self.currentGame.playerAddressCoordinates?.latitude = each.value["playerLatitude"] as! Double
                        print(self.theApp.playerAddressCoordinates?.latitude)
                        print(self.currentGame.currentGameIDKey)

                    }
                }
            })

这就是它在控制台中的打印方式:
Snap (currentGame) {
    "-KUZBVvbtVhJk9EeQAiL" =     {
        date = "2016-10-20 18:24:08 -0400";
        playerAdress = "47 Calle Tacuba Mexico City DF 06010";
        playerLatitude = "19.4354257";
        playerLongitude = "-99.1365724";
    };
}

currentGameIDKey被保存,但self.currentGame.playerAddressCoordinates不被保存。

最佳答案

假设您的节点“currentGame”中有多个对象,并且您希望从所有对象中提取玩家地址坐标和当前游戏id密钥,那么您可以这样做:

self.ref.child("users").child(userFound.userRef!).child("currentGame").observeSingleEvent(of: .value, with: { (snapshot) in
            if(snapshot.exists()) {
                let enumerator = snapshot.children
                while let listObject = enumerator.nextObject() as? FIRDataSnapshot {
                    self.theApp.currentGameIDKey = listObject.key
                    let object = listObject.value as! [String: AnyObject]
                    self.currentGame.playerAddressCoordinates?.latitude = object["playerLatitude"] as! Double
                    print(self.theApp.playerAddressCoordinates?.latitude)
                    print(self.currentGame.currentGameIDKey)
                }
            }

根据您的数据库设计,您没有以正确的方式访问“playerLatitude”“playerLatitude”是快照子对象的子对象。
我猜你正在使用childByAutoId()插入“当前游戏”。因此,您需要将其进一步展开一层才能访问它。
此外,如果您只能访问一个孩子,还可以使用:
self.ref.child("users").child(userFound.userRef!).child("currentGame").observeSingleEvent(of: .value, with: { (snapshot) in
            if(snapshot.exists()) {
                    let currentGameSnapshot = snapshot.children.allObjects[0] as! FIRDataSnapshot
                    self.theApp.currentGameIDKey = currentGameSnapshot.key
                    self.currentGame.playerAddressCoordinates?.latitude = currentGameSnapshot.childSnapshot(forPath: "playerLatitude").value as! Double
                    print(self.theApp.playerAddressCoordinates?.latitude)
                    print(self.currentGame.currentGameIDKey)

            }

希望这有帮助!

08-19 13:56