Swift Firebase 存储如何检索具有未知名称（NSUUID）的图像

Question

我正在创建一个函数来检索作为用户图像的 url。但是，我的上传图片名称功能是由 NSUUID 创建的。因此，我不知道每个用户个人资料图片的名称是什么。如何改进我的代码以获取每个用户的用户 imgae，而不是硬编码 img 名称？

func getUserProfilePic(){
let uid = FIRAuth.auth()?.currentUser?.uid
let profilePath = refStorage.child("\(uid)").child("profilePic/xxxxx.jpg") // xxxxx = NSUUID

profilePath.dataWithMaxSize(1 * 1024 * 1024) { (data, error) -> Void in
  if (error != nil) {
    print("got no pic")
  } else {

    let profilePic: UIImage! = UIImage(data: data!)
    self.imageV.image = profilePic
    print("got pic")
  }
}
}

路径是uid/profilePic/----

上传功能

  func uploadingPhoto(){
let uid = FIRAuth.auth()?.currentUser?.uid
let imgName = NSUUID().UUIDString + ".jpg"
let filePath = refStorage.child("\(uid!)/profilePic/\(imgName)")
var imageData = NSData()
imageData = UIImageJPEGRepresentation(profilePic.image!, 0.8)!

let metaData = FIRStorageMetadata()
metaData.contentType = "image/jpg"

let uploadTask = filePath.putData(imageData, metadata: metaData){(metaData,error) in
  if let error = error {
    print(error.localizedDescription)
    return
}else{
    let downloadURL = metaData!.downloadURL()!.absoluteString
    let uid = FIRAuth.auth()?.currentUser?.uid
    let userRef = self.dataRef.child("user").child(uid!)
    userRef.updateChildValues(["photoUrl": downloadURL])
    print("alter the new profile pic and upload success")

  }

}

Answer 1

有两种方法可以解决这个问题：-

1.) 将用户 profile_picture 的 Firebase 存储路径存储在您的 Firebase 数据库中，并在每次开始下载个人资料图片之前检索。

2.) 每次您的用户上传个人资料图片时，将文件路径存储在 CoreData 中，并每次点击 path 以获取您存储该用户 profile_pic 的文件路径。

存储路径：-

func uploadSuccess(metadata : FIRStorageMetadata , storagePath : String)
{   
    print("upload succeded!")
    print(storagePath)

    NSUserDefaults.standardUserDefaults().setObject(storagePath, forKey: "storagePath.\((FIRAuth.auth()?.currentUser?.uid)!)")
    //Setting storagePath : (file path of your profile pic in firebase) to a unique key for every user "storagePath.\((FIRAuth.auth()?.currentUser?.uid)!)"
    NSUserDefaults.standardUserDefaults().synchronize()

 }

检索您的路径，每次您开始下载图像时：-

let storagePathForProfilePic = NSUserDefaults.standardUserDefaults().objectForKey("storagePath.\((FIRAuth.auth()?.currentUser?.uid)!)") as? String

注意：- 我使用的是currentUser ID，你可以使用 USER SPECIFIC id，如果你想下载多个用户的个人资料图片，你需要做的就是把他们的uid 放在适当的位置。

Answer 2

我强烈建议同时使用 Firebase 存储和 Firebase 实时数据库来存储该 UUID -> URL 映射，并“列出”文件。 Realtime Database will handle offline use cases 也喜欢 Core Data，所以真的没有理由与 Core Data 或 NSUserDefaults 混为一谈。下面是一些显示这些部分如何交互的代码：

共享：

// Firebase services
var database: FIRDatabase!
var storage: FIRStorage!
...
// Initialize Database, Auth, Storage
database = FIRDatabase.database()
storage = FIRStorage.storage()

上传：

let fileData = NSData() // get data...
let storageRef = storage.reference().child("myFiles/myFile")
storageRef.putData(fileData).observeStatus(.Success) { (snapshot) in
  // When the image has successfully uploaded, we get it's download URL
  let downloadURL = snapshot.metadata?.downloadURL()?.absoluteString
  // Write the download URL to the Realtime Database
  let dbRef = database.reference().child("myFiles/myFile")
  dbRef.setValue(downloadURL)
}

下载：

let dbRef = database.reference().child("myFiles")
dbRef.observeEventType(.ChildAdded, withBlock: { (snapshot) in
  // Get download URL from snapshot
  let downloadURL = snapshot.value() as! String
  // Create a storage reference from the URL
  let storageRef = storage.referenceFromURL(downloadURL)
  // Download the data, assuming a max size of 1MB (you can change this as necessary)
  storageRef.dataWithMaxSize(1 * 1024 * 1024) { (data, error) -> Void in
    // Do something with downloaded data...
  })
})

有关详细信息，请参阅Zero to App: Develop with Firebase，它是associated source code，了解如何执行此操作的实际示例。