Question

我正在尝试学习firebase.firebase上有两个文件夹

1）VDBackgroundFrames / 2）VDFrames /

在两个文件夹中，我们都有4张图像-VDBG2.png，VDBG3.png，VDBG4.png，VDBG5.png。

我可以使用以下代码从firebase一次访问一张图像：-

 func firebaseSetUp(){

        let store = Storage.storage()
        let storeRef = store.reference()
        let userProfilesRef = storeRef.child("VDBackgroundFrames/VDBG11.jpg")
        userProfilesRef.downloadURL { (url,error) in
            if error != nil {
                print("error?.localizedDescription",error?.localizedDescription)
                return
            }else{
                print("url",url!)
            }
        }
    }

// ==========更新代码==== //

func firebaseSetUp(){

            let store = Storage.storage()
            let storeRef = store.reference()
            let userProfilesRef = storeRef.child("VDBackgroundFrames/")
            userProfilesRef.observe(.childAdded, with: { [weak self] (snapshot) -> Void in
                guard let strongSelf = self else { return }
                //Logic to extract urls...

                }, changeHandler: (StorageReference, NSKeyValueObservedChange<Value>) -> Void)

    }

我得到的输出如下：-

URL

https://firebasestorage.googleapis.com/v0/b/celebrations-8edf8.appspot.com/o/VDBackgroundFrames%2FVDBG11.jpg?alt=media&token=ae0910d1-2139-4443-b19a-02edde2f9b17

我实际上想分别从文件夹VDBackgroundFrames和VDFrames一起访问所有4个图像。请提出可能的实现方法。任何建议或指导都是可取的。预先感谢。

Answer 1

只需直接访问根文件夹而不是直接访问子文件夹，这样您将获得该文件夹中的所有节点/图像，如下所示：

func firebaseSetUp(){

    let store = Storage.storage()
    let storeRef = store.reference()
    let userProfilesRef = storeRef.child("VDBackgroundFrames/")
    userProfilesRef.observe(.childAdded, with: { [weak self] (snapshot) -> Void in
        guard let strongSelf = self else { return }
        //Logic to extract urls...

    } 
}

Answer 2

DownloadURL一次只包含一个字符串。如果您想将文件夹中的所有文件显示在像我这样的表格视图中，请使用完整代码：

   import UIKit import Firebase
My very First View Controller-

   class FolderList: UIViewController {
       var folderList: [StorageReference]?
        lazy var storage = Storage.storage()

       @IBOutlet weak var tableView : UITableView!

       override func viewDidLoad() {
           super.viewDidLoad()
   self.storage.reference().child("TestFolder").listAll(completion: {
   (result,error) in
               print("result is \(result)")
               self.folderList = result.items
               DispatchQueue.main.async {
                   self.tableView.reloadData()
               }
           })
       } }

   extension FolderList : UITableViewDataSource {
       func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
           return folderList?.count ?? 0
       }

       func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
           guard let cell = tableView.dequeueReusableCell(withIdentifier: "FolderListCell", for:
   indexPath) as? FolderListCell else {return UITableViewCell()}
           cell.itemName.text = folderList?[indexPath.row].name
           return cell
       }

       func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
           return 64.0
       } }


   extension FolderList : UITableViewDelegate {
       func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
           let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
           guard let downloadVC = storyBoard.instantiateViewController(withIdentifier:
   "DownloadedItemView") as? DownloadedItemView else {
               return
           }
           downloadVC.storageRef = folderList?[indexPath.row]
           self.navigationController?.pushViewController(downloadVC, animated: true)
       } 
}





And here is you DownloadedItemView, which will open the images you selected from the list in a view:

import UIKit
import WebKit
import Firebase

class DownloadedItemView: UIViewController {
    @IBOutlet weak var webView : WKWebView!
    var downloadItemURL : String?
    var storageRef : StorageReference?


    override func viewDidLoad() {
        super.viewDidLoad()

        storageRef?.downloadURL(completion: {(downloadURL,error) in
            print("url is \(downloadURL)")
            DispatchQueue.main.async {
                guard let url = downloadURL else {return}
                let urlrequest = URLRequest(url: url)
                self.webView.load(urlrequest)
            }
        })
    }
}




Your each cell:

   class FolderListCell: UITableViewCell {

       @IBOutlet weak var itemName : UILabel!

   }

从iOS中Firebase上的特定文件夹下载所有图像

2 个答案: