swift - 注册过程中 Firebase 数据无效

Question

目前，我在注册过程中结合使用了 Firebase 身份验证、数据库和存储。

@objc func handleSignUp() {

        guard let email = emailTextField.text else { return }
        guard let password = passwordTextField.text else { return }
        guard let fullName = fullNameTextField.text else { return }
        guard let username = usernameTextField.text else { return }

        Auth.auth().createUser(withEmail: email, password: password) { (user, error) in

            //handle error
            if let error = error {

                print("Failed to create user with error", error.localizedDescription)
                return
            }

            //set profile image
            guard let profileImage = self.plusPhotoButton.imageView?.image else { return }

            //upload data
            guard let uploadData = profileImage.jpegData(compressionQuality: 0.3) else { return }

            //place image in firbase storage
            let filename = NSUUID().uuidString

            let storage = Storage.storage()
            let storageReference = storage.reference()

            let imagesReference = storageReference.child("profile_images")

            let uploadReference = imagesReference.child(filename)
            uploadReference.putData(uploadData, metadata: nil) { (metadata, error) in

                //handle error
                if let error = error {

                    print("Failed to upload image to Firebase Storage with error", error.localizedDescription)
                }

                //profile image url
                let profileImageURL = uploadReference.downloadURL

                //user id
                let uid = user?.user.uid

                let dictionaryValues = ["name": fullName, "username": username, "profileImageURL": profileImageURL]

                let values = [uid: dictionaryValues]

                //save user info to database
                Database.database().reference().child("users").updateChildValues(values) { (error, ref) in

                    print("Successfully created user and saved information to database")

                }
            }
        }

这应该是代码，应该可以正常工作。 然而，xCode 给了我这个错误:

Heterogeneous collection literal could only be inferred to '[String : Any]'; add explicit type annotation if this is intentional

并且建议我改变

let dictionaryValues = ["name": fullName, "username": username, "profileImageURL": profileImageURL]

至

let dictionaryValues = ["name": fullName, "username": username, "profileImageURL": profileImageURL] as [String : Any]

结果，我可以编译并运行该项目。

但是，当我按下注册按钮并运行给定的函数时，控制台显示此错误:

2019-09-30 19:15:13.049986+0200 5iveli0ns[965:28839] [] nw_connection_receive_internal_block_invoke [C2] Receive reply failed with error "Operation canceled"

最后我收到一个运行时异常:

*** Terminating app due to uncaught exception 'InvalidFirebaseData', reason: '(updateChildValues:withCompletionBlock:) Cannot store object of type __SwiftValue at profileImageURL. Can only store objects of type NSNumber, NSString, NSDictionary, and NSArray.'

这是 xCode 11/Firebase 5.x.x 相关问题吗？

Answer 1

一般来说，字典根据它们包含的数据推断其结构。例如

let dict = [
   "name": "Leroy",
   "fav_food": "Pizza"
]

是一个[String: String]字典

同样

let dict = [
   "name": "Leroy"
   "age": 25
]

是一个[String: Int]字典。

你拥有的是

let dict = [
   "name": "Leroy",
   "username": "some username"
   "profileImageUrl": URL //oops, not a string, its a URL!
]

当Dictionary值一致时，可以定义[String: String]。但是，当值类型发生变化时，它们是 [String: Any]

另一个问题是 Firebase 不支持 URL 类型，因此即使您使用 [String: Any] 字典，Firebase 也会提示 - 如错误所示。

修复很简单 - 只需使用路径，它是 url 的字符串

if let url = uploadReference.downloadURL {
    let path = url
    let dict = [
       "name": "Leroy",
       "username": "some username",
       "path": path //it's a string
    ]
    //write dict to Firebase
}