ios - Swift 3 - 将 Firebase 数据保存在数组中

Question

我尝试将 Firebase 数据保存在数组中，但数组计数每次都是 0。

override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        getAllSkateShops()
}


func getAllSkateShops() {

        ref = FIRDatabase.database().reference()

        ref.child("Shops").observeSingleEvent(of: .value, with: { (snapshot) in

            //var newShops: [SkateShop] = []

            for item in snapshot.children {

                let skateShopItem = SkateShop(snapshot: item as! FIRDataSnapshot)
                self.shops.append(skateShopItem)
                DispatchQueue.main.async(execute: {
                  print("OBSERVE SHOP COUNT: \(self.shops.count)")
                })
            }

        })
}

在函数 viewDidLoad() 中，self.shop.count 为零，但我需要这个包含所有商店的数组。

我希望有人能帮助我；)

Answer 1

我遇到了同样的问题，不知道为什么会这样，但在 DispatchQueue.main.async 中执行(已编辑):

func getAllSkateShops() {

    ref = FIRDatabase.database().reference()

    ref.child("Shops").observeSingleEvent(of: .value, with: { (snapshot) in

        //var newShops: [SkateShop] = []

        for item in snapshot.children {

            let skateShopItem = SkateShop(snapshot: item as! FIRDataSnapshot)
            self.shops.append(skateShopItem)
            self.shops2.append(skateShopItem)
            DispatchQueue.main.async(execute: {
                var temporaryArray = self.shop2
                self.shop = temporaryArray
            })
        }

    })
}

如果这不起作用评论，我会提供另一个可能有效的选项。