使用Swift iOS从Firebase中的子子项检索所有值

Question

我正在尝试从Firebase的子子中检索所有值以显示在集合视图中的标签中.我必须得到连接视图单元的连接插座,并有一个视图控制器有一个图像和三个标签.在最后一个标签中,我想从firebase child获得所有价格值.

Firebase结构

视图控制器

检索值

  import UIKit
  import  Firebase
 class CakeViewController:  UIViewController , UICollectionViewDelegate,   UICollectionViewDataSource {

@IBOutlet weak var manuCake: UIBarButtonItem!

@IBOutlet weak var cakeCollectionView: UICollectionView!


struct cakeObject {

    var cakeImage : UIImage
    var cakeEnglichName: String
    var cakeUrduName : String
    var cakeRate : String
    var key : String



}

var cakeArray : [cakeObject] = []



override func viewDidLoad() {
    super.viewDidLoad()

    manuCake.target = revealViewController()
    manuCake.action = #selector(SWRevealViewController.revealToggle(_:))
    self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())



    let ref = FIRDatabase.database().reference().child("Hyderabad").child("Bakery").child("Cake")

    ref.observeSingleEvent(of: .value, with: { (snapshot) in
        if snapshot.exists() {


            print(snapshot.value as Any)
            let cakeData = snapshot.value as! [String:String]
                for (key,value) in cakeData{
                    //Can set cakeImage and cakeUrduName as per your project
                    cakeArray.append(cakeObject(cakeImage: #imageLiteral(resourceName: "bakery_almond_cake"),cakeEnglinhName: key, cakeUrduName: "????? ???", cakeRate: "\(value)/kg"))
                }
                self.cakeCollectionView.reloadData()
            }

    })



    cakeCollectionView.delegate = self
    cakeCollectionView.dataSource = self

    // Do any additional setup after loading the view.
}





func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return cakeArray.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CakeCollectionViewCell", for: indexPath)
        as! CakeCollectionViewCell

    cell.cakeImageView.image = cakeArray[indexPath.item].cakeImage
    cell.cakeEngLabs.text = cakeArray[indexPath.item].cakeEnglichName
    cell.cakeUrLabs.text = cakeArray[indexPath.item].cakeUrduName
    cell.cakeRateLabs.text =  cakeArray[indexPath.item].key

    return cell

}



override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

最新的错误

另一种方式同一类

 import UIKit
 import  Firebase
 class CakeViewController:  UIViewController , UICollectionViewDelegate,   UICollectionViewDataSource {

@IBOutlet weak var manuCake: UIBarButtonItem!

@IBOutlet weak var cakeCollectionView: UICollectionView!


struct cakeObject {

    var cakeImage : UIImage
    var cakeEnglichName: String
    var cakeUrduName : String
    //var cakeRate : String
    var key : String



}

var cakeArray : [cakeObject] = []



override func viewDidLoad() {
    super.viewDidLoad()

    manuCake.target = revealViewController()
    manuCake.action = #selector(SWRevealViewController.revealToggle(_:))
    self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())



    let ref = FIRDatabase.database().reference().child("Hyderabad").child("Bakery").child("Cake").child("Almond_Cake")

    ref.observeSingleEvent(of: .value, with: { (snapshot) in
        if snapshot.exists() {


            print(snapshot.value as Any)
             let cakeData = snapshot.value as! [String:String]
                for (key,value) in cakeData{
                    //Can set cakeImage and cakeUrduName as per your project
                    self.cakeArray.append(cakeObject(cakeImage: #imageLiteral(resourceName: "bakery_almond_cake"),cakeEnglichName: key, cakeUrduName: "????? ???", key: "\(value)/kg"))
                }
                self.cakeCollectionView.reloadData()
            }
       })



    cakeCollectionView.delegate = self
    cakeCollectionView.dataSource = self

    // Do any additional setup after loading the view.
}





func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return cakeArray.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CakeCollectionViewCell", for: indexPath)
        as! CakeCollectionViewCell

    cell.cakeImageView.image = cakeArray[indexPath.item].cakeImage
    cell.cakeEngLabs.text = cakeArray[indexPath.item].cakeEnglichName
    cell.cakeUrLabs.text = cakeArray[indexPath.item].cakeUrduName
    cell.cakeRateLabs.text =  cakeArray[indexPath.item].key

    return cell

}



override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

另一种方法错误

Answer 1

您收到以下错误，因为该值不是字典数组，而是字符串。

\n\n

if let cake = snapshot.value![a] as? [[String:String]]\n

\n\n

它应该是

\n\n

if let cake = snapshot.value![a] as? String\n

\n\n

在fruitArray中分配蛋糕率后看不到fruitArray的使用

\n\n

我建议你填写 cakeArray 如下代码：

\n\n

print(snapshot.value as Any)\nlet cakeData = snapshot.value as! [String:String]\n    for (key,value) in cakeData{\n           //Can set cakeImage and cakeUrduName as per your project\n           cakeArray.append(cakeObject(cakeImage: #imageLiteral(resourceName: "bakery_almond_cake"),cakeEnglinhName: key, cakeUrduName: "\xd8\xa2\xd9\x84\xd9\x85\xd9\x86\xda\x91 \xda\xa9\xdb\x8c\xda\xa9", cakeRate: "\\(value)/kg"))                  \n      }\n    self.cakeCollectionView.reloadData()\n

\n\n

第二个错误：我没有看到任何对象作为蛋糕结构中的关键。所以编译器给出错误。您正在为 的上一行赋值cakeRateLabs。因此无需再次分配只需删除/注释即可cell.cakeRateLabs.text = cakeArray[indexPath.item].key。

\n\n

希望这一定能解决您的错误并获得您想要的输出。

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