从主视图控制器发送Firebase数据到详细视图控制器

Question

我能够创建类似于Instagram的UICollection View feed，但我不确定如何选择单元格并转到更详细的视图控制器。这是我的主视图控制器的样子。 “

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) 


     } }} 

这里是我的数据库看起来像：

//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 
     } 
    }) 

以上就是我的详细视图控制器。但是，当单击单元格时，我的信息不通过

Answer 1

你需要给从细胞，而不是view.Like图像显示赛格瑞下面

然后修改代码，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) 


     } }} 

然后在DetailsViewController代码就会像下面（无需再次参考firebase，因为您已经拥有所有信息）：

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:") 
       } 

将代码写入viewDidLoad。

Answer 2

这似乎是重复的。在视图控制器之间传递数据的一个很好的例子可以在这里找到：Passing Data between View Controllers。

构建您的数据也很重要。如果您的Firebase数据库收到了Post对象，则应该创建一个本地Post对象并引用该对象。在UICollectionViewCell上，可以使用选定的indexPath来获取指定给该单元格的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) 


    })} } }}