ios - 数据服务错误未解决

Question

我遇到的许多问题之一就是这个错误:

Type 'DataService' has no member 'dataService'

我一直在寻找，但找不到任何明确的信息。感谢您的帮助。我不确定问题是什么。我一开始以为服务已更改为数据库，但这也不正确，除非我完全错了。

import UIKit
import Firebase

class UserFeedTableViewController: UITableViewController {
    let ref = Database.database().reference(withPath: "userpost-items")

    var userpost = [UserPost]()

    override func viewDidLoad() {
        super.viewDidLoad()

        // observeEventType is called whenever anything changes in the Firebase - new Jokes or Votes.
        // It's also called here in viewDidLoad().
        // It's always listening.

        DataService.dataService.USERPOST_REF.observe(.value, with: { snapshot in
            // The snapshot is a current look at our jokes data.
            self.userposts = []

            if let snapshots = snapshot?.children.allObjects as? [FDataSnapshot] {
                for snap in snapshots {
                    // Make our jokes array for the tableView.

                    if let postDictionary = snap.value as? Dictionary<String, AnyObject> {
                        let key = snap.key
                        let userpost = UserPost(key: key!, dictionary: postDictionary)

                        // Items are returned chronologically, but it's more fun with the newest jokes first.

                        self.userpost.insert(userpost, at: 0)
                    }
                }
            }

            // Be sure that the tableView updates when there is new data.

            self.tableView.reloadData()
        })
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return userpost.count
    }

    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let userpost = self.userpost[indexPath.row]

        // We are using a custom cell.
        if let cell = tableView.dequeueReusableCell(withIdentifier: "UserPostCellTableViewCell") as? UserPostTableViewCell {
            // Send the single user post to configureCell() in UserPostCellTableViewCell.
            cell.configureCell(userpost: userpost)

            return cell
        } else {
            return UserPostTableViewCell()
        }
    }
}

Answer 1

我发表了评论，但实际代码将更清楚地阐明我建议的模式。还有 100 种其他方法可以实现此目的。 (注:Swift 4、Firebase 4)

class UserFeedTableViewController: UITableViewController {
    var ref: DatabaseReference!

    var userpost = [UserPost]()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.ref = Database.database().reference()
    }

    func loadPosts() {
       let postRef = self.ref.child("posts")
       postRef.observe(.value, with: { snapshot in
          self.userposts = []
          ...
    }