问题
Hello everyone I am struggling with retrieving my image from firebase into my Image view. The first thing I do is create a method to retrieve the photo data in an array here is that code:
class PhotoService {
static func retrievePhotos(completion: @escaping ([Photo]) -> Void) {
//get a databas refrence
let db = Firestore.firestore()
//get data from "photos" collection
db.collection("photos").getDocuments { (snapshot, Error) in
//check for errors
if Error != nil {
//error in retrieving photos
return
}
//get all the documents
let documents = snapshot?.documents
//check that documents arent nil
if let documents = documents {
//create an array to hold all of our photo structs
var photoArray = [Photo]()
//loop through documents, get a photos struct for each
for doc in documents {
//create photo struct
let p = Photo(snapshot: doc)
if p != nil {
//store it in an array
photoArray.insert(p!, at: 0)
}
}
//pass back the photo array
completion(photoArray)
}
}
}
Then I call that class and attempt to display the Image in the image view as so:
@IBOutlet var profilePictureImageView: UIImageView!
var photos = [Photo]()
override func viewDidLoad() {
super.viewDidLoad()
//call the photo service to retrieve the photos
PhotoService.retrievePhotos { (retrievedPhotos) in
//set the photo array to the retrieved photos
self.photos = retrievedPhotos
//make the image view a circle
self.profilePictureImageView.layer.cornerRadius = self.profilePictureImageView.bounds.height / 2
self.profilePictureImageView.clipsToBounds = true
//make the image view display the photo
var photo:Photo?
func displayPhoto(photo:Photo) {
//check for errors
if photo.photourl == nil {
return
}
//download the image
let photourl = URL(string: photo.photourl!)
//check for erorrs
if photourl == nil {
return
}
//use url session to download the image asynchronously
let session = URLSession.shared
let dataTask = session.dataTask(with: photourl!) { (data, response, Error) in
//check for errors
if Error == nil && data != nil {
//let profilePictureImageView = UIImage()
let image = UIImage(data: data!)
//set the image view
DispatchQueue.main.async {
self.profilePictureImageView.image = image
}
}
}
dataTask.resume()
}
}
}
}
Not sure what I am doing wrong, If anyone can tell me what I am doing wrong or what I need to add I would really appreciate it Thank you!
来源：https://stackoverflow.com/questions/62647467/swift-retrieving-firebase-image-into-imageview