ios - 如何检索存储在 firebase 中的图像以在 View ImageView 中显示它

Question

我遇到了如何检索存储在 firebase 中的图像的问题这是我用来存储图像的代码:

@IBAction func AddDeviceButton(sender: AnyObject) {
    if DeviceName.text == "" || Description.text == "" || ImageView.image == nil {
        let alert = UIAlertController(title: "عذرًا", message:"يجب عليك تعبئة معلومات الجهاز كاملة", preferredStyle: .Alert)
        alert.addAction(UIAlertAction(title: "نعم", style: .Default) { _ in })
        self.presentViewController(alert, animated: true){}

    } else {

        let imageName = NSUUID().UUIDString
        let storageRef = FIRStorage.storage().reference().child("Devices_Images").child("\(imageName).png")

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

        if let uploadData = UIImagePNGRepresentation(self.ImageView.image!) {
            storageRef.putData(uploadData, metadata: metaData, completion: { (data, error) in
                if error != nil {
                    print(error)

                } else {
                    print("Image Uploaded Succesfully")
                    let profileImageUrl = data?.downloadURL()?.absoluteString

                    //

                    let DeviceInfo = [
                        "ImageUrl":profileImageUrl!,
                        "DeviceName":self.DeviceName.text!,
                        "Description":self.Description.text!,
                        "Category":self.itemSelected
                    ]

                    let DeviceInformation = [
                        "ImageUrl":profileImageUrl!,
                        "DeviceName":self.DeviceName.text!,
                        "Description":self.Description.text!,
                        "Category":self.itemSelected,
                        "name": self.globalUserName,
                        "email":self.globalEmail ,
                        "city": self.globalCity,
                        "phone": self.globalPhone
                    ]


                    self.ref.child("Devices").child(FIRAuth.auth()!.currentUser!.uid).observeSingleEventOfType(.Value, withBlock: {(snapShot) in
                        if snapShot.exists(){
                            let numberOfDevicesAlreadyInTheDB = snapShot.childrenCount
                            if numberOfDevicesAlreadyInTheDB < 3{
                                let newDevice = String("Device\(numberOfDevicesAlreadyInTheDB+1)")
                                let userDeviceRef = self.ref.child("Devices").child(FIRAuth.auth()!.currentUser!.uid)
                                userDeviceRef.observeSingleEventOfType(.Value, withBlock: {(userDevices) in
                                    if let userDeviceDict = userDevices.value as? NSMutableDictionary{

                                        userDeviceDict.setObject(DeviceInfo,forKey: newDevice)

                                        userDeviceRef.setValue(userDeviceDict)
                                    }
                                })
                            }
                            else{
                                let alert = UIAlertController(title: "عذرًا", message:"يمكنك إضافة ثلاثة أجهزة فقط كحد أقصى", preferredStyle: .Alert)
                                alert.addAction(UIAlertAction(title: "نعم", style: .Default) { _ in })
                                self.presentViewController(alert, animated: true){}
                            }
                        }else{
                          self.ref.child("Devices").child(FIRAuth.auth()!.currentUser!.uid).setValue(["Device1" : DeviceInfo])
                             self.ref.child("UserDevices").childByAutoId().setValue(DeviceInformation)

                        }
                    })

                    //

                } })
        }


    } //Big Big Else

} //AddDeviceButton

我只想将图像从 firebase 存储加载到用户配置文件中，这样每次用户登录到他的配置文件时，他都可以看到他上传到应用程序的所有图像

Answer 1

我们强烈建议结合使用 Firebase 存储和 Firebase 实时数据库来实现这一目标。这是一个完整的例子:

共享:

// Firebase services
var database: FIRDatabase!
var storage: FIRStorage!
...
// Initialize Database, Auth, Storage
database = FIRDatabase.database()
storage = FIRStorage.storage()
...
// Initialize an array for your pictures
var picArray: [UIImage]()
let myUserId = ... // get this from Firebase Auth or some other ID provider

上传:

let fileData = NSData() // get data...
let storageRef = storage.reference().child("userFiles/\(myUserId)/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("userFiles/\(myUserId)/myFile")
  dbRef.setValue(downloadURL)
}

下载:

let dbRef = database.reference().child("userFiles/\(myUserId)")
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
    // Create a UIImage, add it to the array
    let pic = UIImage(data: data)
    picArray.append(pic)
  })
})

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