Question

对Swift来说很新，但是我想做一个控制器的演示，当我打电话给那个控制器时，我没有附上textLabel的文字。当我第一次运行应用程序时，我做对了，但是当我尝试添加新的评论时，它不起作用。这是我的代码

override func viewDidLoad() {
    super.viewDidLoad()
    observeReviews()
    navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Sign Out", style: .plain, target: self, action: #selector(handleLogout))
    let newReview = UIBarButtonItem(barButtonSystemItem: .compose, target: self, action: #selector(handleNewReview))
    let addCategory = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(handleNewCategory))
    navigationItem.rightBarButtonItem = addCategory
    navigationItem.rightBarButtonItems?.append(newReview)
    tableView.register(ReviewCell.self, forCellReuseIdentifier: cellId)
    checkIfUserIsLoggedIn()
}

func observeReviews() {
    let ref = Database.database().reference().child("reviews").queryOrdered(byChild: "timestamp")
    ref.observe(.childAdded, with: { (snapshot) in
        if let dictionary = snapshot.value as? [String:AnyObject] {
            let review = Review()
            review.gameId = dictionary["gameId"] as? String
            review.userId = dictionary["userId"] as? String
            review.reviewText = dictionary["reviewText"] as? String
            review.rate = dictionary["rate"] as? Int
            review.timestamp = dictionary["timestamp"] as? Int
            self.reviews.append(review)
            DispatchQueue.main.async {
                self.tableView.reloadData()
            }
        }
    }, withCancel: nil)
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! ReviewCell
    let review = reviews[indexPath.row]

    cell.review = review

    return cell
}

override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    return 72
}


}

class ReviewCell: UITableViewCell {
var review: Review? {
    didSet {
        var rate = ""
        if let rating = review?.rate {
            switch rating {
            case 0:
                rate = "It's awful"
                break
            case 1:
                rate = "Nothing special"
                break
            case 2:
                rate = "Meh"
                break
            case 3:
                rate = "Maybe I'll play it if I don't have Internet"
                break
            case 4:
                rate = "IT'S AWESOME"
                break
            default:
                rate = "none"
                break
            }
        }
        let userId = review?.userId
        let refUsers = Database.database().reference().child("users").child(userId!)
        refUsers.observeSingleEvent(of: .value, with: { (snapUsers) in
            if let dictUsers = snapUsers.value as? [String: AnyObject] {
                let user = User()
                user.username = dictUsers["username"] as? String
                user.email = dictUsers["email"] as? String
                user.profilePicture = dictUsers["profileImageUrl"] as? String
                self.textLabel?.text = user.username! + " rated "
            }
        }, withCancel: nil)

        let gameId = review!.gameId
        let refGames = Database.database().reference().child("games").child(gameId!)
        refGames.observeSingleEvent(of: .value, with: { (snapGames) in
            if let dictGames = snapGames.value as? [String: AnyObject] {
                let game = Game()
                game.gid = gameId
                game.name = dictGames["name"] as? String
                game.desc = dictGames["desc"] as? String
                game.coverPhoto = dictGames["gameCover"] as? String
                self.textLabel?.text?.append(game.name! + " as " + "\"" + rate + "\"")
                if let gameCoverUrl = game.coverPhoto {
                    self.gameCoverView.loadImageWithCacheFromUrlString(urlString: gameCoverUrl)

                }
            }
        }, withCancel: nil)
        self.detailTextLabel?.text = "Tap to see more"
    }
}

override func prepareForReuse() {
    print(textLabel?.text)
}

override func layoutSubviews() {
    super.layoutSubviews()

    textLabel?.frame = CGRect(x: 64, y: textLabel!.frame.origin.y - 2, width: textLabel!.frame.width, height: textLabel!.frame.height)
    detailTextLabel?.frame = CGRect(x: 64, y: detailTextLabel!.frame.origin.y + 2, width: detailTextLabel!.frame.width, height: detailTextLabel!.frame.height)
}

let gameCoverView: UIImageView = {
    let imageView = UIImageView()
    imageView.translatesAutoresizingMaskIntoConstraints = false
    imageView.contentMode = .scaleAspectFill
    return imageView
}()

override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
    super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)

    addSubview(gameCoverView)
    //x,y,width,height constraints
    gameCoverView.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 8).isActive = true
    gameCoverView.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
    gameCoverView.widthAnchor.constraint(equalToConstant: 48).isActive = true
    gameCoverView.heightAnchor.constraint(equalToConstant: 48).isActive = true
}



required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}
}

所以，在viewDidLoad()我正在调用observeReviews()从Firebase获取评论，然后当我填充tableview时，我正在使用特殊类来获取该单元格。所以，当我第一次运行应用程序时，我得到了所有的东西，但是当我为某些游戏添加新的评论时，从该视图控制器我呈现这个视图控制器，而我得到的只是第一个，例如：

正确的一个：弗拉基米尔认为CandyCrushSaga很棒

我得到的：弗拉基米尔评价

Answer 1

而不是self.textLabel?.text?.append(game.name! + " as " + "\"" + rate + "\"")尝试这个：

self.textLabel?.text = "\(game.name!) as \(your variable) rate \(your variable)"

或

self.textLabel?.text = self.textLabel?.text + "Text \(your variable)"

cell.textLabel.text没有附加

1 个答案: