ios - 将 Firebase 数据从主视图 Controller 发送到详细 View Controller

Question

我能够创建类似于 Instagram 的 UICollection View 提要，但我不确定如何选择单元格并转到更详细的 View Controller 。这是我的主视图 Controller 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)


        }  }}

这是我的数据库的样子:

    //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  
        }
    })  

上面是我的详细 View Controller 。然而，当我点击单元格时，我的信息没有被传递

Answer 1

您需要从单元格而不是 View 提供转场。如下图所示

然后修改你的代码如下所示:

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 中的代码将如下所示(无需再次引用 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:" )
                }

在viewDidLoad中编写代码。