從主視圖控制器發送Firebase數據到詳細視圖控制器

Question

我能夠創建類似於Instagram的UICollection View feed，但我不確定如何選擇單元格並轉到更詳細的視圖控制器。這是我的主視圖控制器的樣子。 「

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { 



    performSegue(withIdentifier: "details", sender: self) 
    } 

override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
    if segue.identifier == "details" { 


     if let indexPaths = self.collectionView!.indexPathsForSelectedItems{ 

    let vc = segue.destination as! MainViewController 
    let indexPath = indexPaths[0] as NSIndexPath 
    let post = self.posts[indexPath.row] as! [String: AnyObject] 
     let Booked = post["title"] as? String 
     let Authors = post["Author"] as? String 
     let ISBNS = post["ISBN"] as? String 
     let Prices = post["Price"] as? String 
     let imageNames = post["image"] as? String 
     vc.Booked = Booked 
     vc.Authors = Authors 
     vc.ISBNS = ISBNS 
     vc.Prices = Prices 
     vc.imageNames = imageNames 

      print(indexPath.row) 


     } }} 

這裏是我的數據庫看起來像：

//Detailed View Controller 
    FIRDatabase.database().reference().child("posts").child(self.loggedInUser!.uid).observeSingleEvent(of: .value, with: { (snapshot:FIRDataSnapshot) in 
     if let dictionary = snapshot .value as? [String: AnyObject] { 
      self.BookTitle.text = dictionary["title"] as? String 
      self.Author.text = dictionary["Author"] as? String 
      self.ISBN.text = dictionary["ISBN"] as? String 
      self.Price.text = dictionary["Price"] as? String 
      self.Image.image = ["image"] as? UIImage 
     } 
    }) 

以上就是我的詳細視圖控制器。但是，當單擊單元格時，我的信息不通過

Answer 1

你需要給從細胞，而不是view.Like圖像顯示賽格瑞下面

然後修改代碼，如下所示：

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { 
    // No Need to call this performSegue(withIdentifier: "details", sender: self) 
    } 

override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
    if segue.identifier == "details" { 


     if let indexPaths = self.collectionView!.indexPathsForSelectedItems{ 

    let vc = segue.destination as! MainViewController 
    let cell = sender as UICollectionViewCell 
    let indexPath = self.collectionView!.indexPathForCell(cell) 
    let post = self.posts[indexPath.row] as! [String: AnyObject] 
     let Booked = post["title"] as? String 
     let Authors = post["Author"] as? String 
     let ISBNS = post["ISBN"] as? String 
     let Prices = post["Price"] as? String 
     let imageNames = post["image"] as? String 
     vc.Booked = Booked 
     vc.Authors = Authors 
     vc.ISBNS = ISBNS 
     vc.Prices = Prices 
     vc.imageNames = imageNames 

      print(indexPath.row) 


     } }} 

然後在DetailsViewController代碼就會像下面（無需再次參考firebase，因爲您已經擁有所有信息）：

self.BookTitle.text = self.Booked 
      self.Author.text = self.Author 
      self.ISBN.text = self.ISBN 
      self.Price.text = self.Price 
      if let stringImage = self.imageNames as? String { 

      let imageRef = storage.reference(forURL: "gs://gsignme-14416.appspot.com/images/\(stringImage)") 

      imageRef.data(withMaxSize: 25 * 1024 * 1024, completion: { (data, error) -> Void in 
       if error == nil { 
        self.Image.image = UIImage(data: data!) 


       }else { 
        print("Error downloading image:") 
       } 

將代碼寫入viewDidLoad。

Answer 2

這似乎是重複的。在視圖控制器之間傳遞數據的一個很好的例子可以在這裏找到：Passing Data between View Controllers。

構建您的數據也很重要。如果您的Firebase數據庫收到了Post對象，則應該創建一個本地Post對象並引用該對象。在UICollectionViewCell上，可以使用選定的indexPath來獲取指定給該單元格的Post。

Answer 3

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { 
    } 



override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
    if segue.identifier == "details" { 




     if let indexPaths = self.collectionView!.indexPathsForSelectedItems{ 

    let vc = segue.destination as! MainViewController 
      let cell = sender as! UICollectionViewCell 
    let indexPath = self.collectionView!.indexPath(for: cell) 
    let post = self.posts[(indexPath?.row)!] as! [String: AnyObject] 
     let Booked = post["title"] as? String 
     let Authors = post["Author"] as? String 
     let ISBNS = post["ISBN"] as? String 
     let Prices = post["Price"] as? String 
      if let imageNames = post["image"] as? String { 

       let imageRef = storage.reference(forURL: "gs://gsignme-14416.appspot.com/images/") 

       imageRef.data(withMaxSize: 25 * 1024 * 1024, completion: { (data, error) -> Void in 
        if error == nil { 
         let image = UIImage(data: data!) 


        }else { 
         print("Error downloading image:") 
        } 


     vc.Booked = Booked 
     vc.Authors = Authors 
     vc.ISBNS = ISBNS 
     vc.Prices = Prices 
     vc.imageNames = imageNames 

      print(indexPath?.row) 


    })} } }}