如何調用不帶參數的函數來更新接口？

Question

我想更新我的界面與模型我have.I在我的這兩個出口PFTableViewCell ：

class UserFeedCell: PFTableViewCell {

    @IBOutlet weak var likeButton: UIButton!
    @IBOutlet weak var dislikeButton: UIButton!

我想用以下代碼更新這兩個插座按鈕：

var vote: Int = 0 // initialize to user's existing vote, retrieved from the server
var likeCount: Int = 0 // initialize to existing like count, retrieved from the server
var dislikeCount: Int = 0 // initialize to existing dislike count, retrieved from the server

@IBAction func dislikeButton(sender: UIButton) {
    buttonWasClickedForVote(-1)
    print(likeCount)
    print(dislikeCount)
}

@IBAction func likeButton(sender: UIButton) {
    buttonWasClickedForVote(1)
    print(likeCount)
    print(dislikeCount) 
}

private func buttonWasClickedForVote(buttonVote: Int) {
    if buttonVote == vote {
        // User wants to undo her existing vote.
        applyChange(-1, toCountForVote: vote)
        vote = 0
    }

    else {
        // User wants to force vote to toggledVote.
        // Undo current vote, if any.
        applyChange(-1, toCountForVote: vote)

        // Apply new vote.
        vote = buttonVote
        applyChange(1, toCountForVote: vote)
    }
}

private func applyChange(change: Int, toCountForVote vote: Int ) {
    if vote == -1 { dislikeCount += change }
    else if vote == 1 { likeCount += change }
}

private func updateUserInterfaceFromModel() {
    let cell = tableView.dequeueReusableCellWithIdentifier(reuseIdentifier) as! UserFeedCell
    cell.likeButton.selected = vote == 1
    cell.dislikeButton.selected = vote == -1
    cell.likeButton.setTitle("\(likeCount)", forState: .Normal)
    cell.dislikeButton.setTitle("\(dislikeCount)", forState: .Normal)
}

如何更新我的店鋪？ 我嘗試在viewDidLoad調用，但是我的商店沒有更新。

Answer 1

您可以這樣使用：-

 func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cellIdentifier = "TableViewCell" // your cell identifier name in storyboard 
    let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! PFTableViewCell
    cell.likeButton.selected = vote == 1
    cell.dislikeButton.selected = vote == -1
    cell.likeButton.titleLabel!.text = "\(likeCount)"
    cell.dislikeButton.titleLabel!.text = "\(dislikeCount)"
    return cell
}

問題更新后，可以使用awakeFromNib完成此任務...

class UserFeedCell: PFTableViewCell {

@IBOutlet weak var likeButton: UIButton!
@IBOutlet weak var dislikeButton: UIButton!

override func awakeFromNib() {
    super.awakeFromNib()
    likeButton.titleLabel!.text = "\(likeCount)"
    dislikeButton.titleLabel!.text = "\(dislikeCount)"
}

override func setSelected(selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
}

}

Answer 2

viewDidLoad不是在UITableViewCell上設置屬性的正確位置。 您必須等待iOS詢問單元格，然后才能在單元格上設置屬性並返回它。 cellForRowAtIndexPath是正確的方法。 您還需要確保正確設置了正確的屬性（使用indexPath.row ）。