Question

我正在使用Swift 3和Firebase制作iOS应用。我不断收到错误“无法将类型'UserFile'的值转换为预期参数'User'”。这是我的代码：

import Foundation
import Firebase
import FirebaseAuth


class UserAPI {

    var REF_USERS = Database.database().reference().child("users")

    var CURRENT_USER: User? {
        if let currentUser = Auth.auth().currentUser {
            return currentUser
        }
        return nil
    }

    var CURRENT_USER_ID = Auth.auth().currentUser?.uid

    var REF_CURRENT_USER: DatabaseReference? {
        guard let currentUser = Auth.auth().currentUser else {
            return nil
        }
        return REF_USERS.child(currentUser.uid)
    }

    func observeCurrentUser(completion: @escaping (User) -> Void) {
        guard let currentUser = Auth.auth().currentUser else {
            return
        }

        REF_USERS.child(currentUser.uid).observeSingleEvent(of: .value, with: { snapshot in
            if let postDictionary = snapshot.value as? [String: Any] {
                let user = UserFile.transformUser(postDictionary: postDictionary)
                completion(user)        //Cannot convert value of type 'UserFile' to expected argument 'User'
            }
        })
    }

    func observeUser(withID uid:String, completion: @escaping (User) -> Void) {
        REF_USERS.child(uid).observeSingleEvent(of: .value, with: { snapshot in
            if let postDictionary = snapshot.value as? [String: Any] {
                let user = UserFile.transformUser(postDictionary: postDictionary)
                completion(user)        //Cannot convert value of type 'UserFile' to expected argument 'User'
            }
        })
    }

}

'UserFile'是另一个Swift文件，下面是代码：

import Foundation

class UserFile {
    var email: String?
    var profileImageURL: String?
    var username: String?
}

extension UserFile {

    static func transformUser(postDictionary: [String: Any]) -> UserFile {
        let user = UserFile()

        user.email = postDictionary["email"] as? String
        user.profileImageURL = postDictionary["profileImageURL"] as? String
        user.username = postDictionary["username"] as? String

        return user
    }

}

我不知道该怎么做。有什么想法吗？

Answer 1

您的功能显示完成的类型为用户：func observeCurrentUser(completion: @escaping (User) -> Void) {并且您已将UserFile传递给它。

将完成类型更改为UserFile，如下所示：（completion: @escaping (UserFile) -> Void)

无法将'UserFile'类型的值转换为预期参数'User'

1 个答案: