单击 UITableviewCells 时更改 UIButton 标题

Question

我用 VK Api 制作简单的播放器。我想做这个。

当我单击第一首曲目然后第二次将第一个按钮标题“停止”更改为“播放”时自动。

怎么做？

我的播放/停止按钮操作。

func playAction(sender: UIButton!) {
    if sender.currentTitle == "P" {
        let track = dataOfTracks[sender.tag] as trackDoc
        let url = NSURL(string: track.data.url)

        player = AVPlayer(URL: url!)
        player.play()
        sender.setTitle("S", forState: UIControlState.Normal)
    } else if sender.currentTitle == "S" {
        sender.setTitle("P", forState: UIControlState.Normal)
        player.pause()
    }
}

Answer 1

编辑代码细节：

1. 不要每次按钮都重新分配。它必须是 SongsTableViewCell 类的另一个出口（与标签相同）。并从 Interface Builder 设置目标/动作（在“func cellSongClicked”前面添加@IBAction，并从 IB 中按 ctrl-drag）

   2.将以下属性添加到您的类中：private var currentSong : Int? 3) 方法 cellForRowAtIndexPath:

   覆盖 func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

   let cell = tableView.dequeueReusableCellWithIdentifier("SongTitleCell", forIndexPath: indexPath) as SongsTableViewCell
   
   let songDic : NSDictionary = arrSongs.objectAtIndex(indexPath.row) as NSDictionary
   
   cell.lblSongTitle.text = songDic.objectForKey("SongTitle") as? String
   cell.btnPlayPause.tag = indexPath.row
   
   var title : String
   if let _currentSong = currentSong {
       title = indexPath.row == _currentSong ? "Stop" : "Play"
   } else {
       title = "Play"
   }
   cell.btnPlayPause.setTitle(title, forState: UIControlState.Normal)
   
   return cell
   

   }

4) 以及动作：

@IBAction func cellSongClicked (sender : AnyObject ){
    var remote = GetSongData()
    remote.delegate = self

    var btnCurrentPressed = sender as UIButton

    //Play Selected Song
    let songDic : NSDictionary = arrSongs.objectAtIndex(btnCurrentPressed.tag) as NSDictionary

    var rowsToReload = [NSIndexPath]()
    var stopCurrent = false
    if let _currentSong = currentSong {
        if btnCurrentPressed.tag == _currentSong {
            stopCurrent = true
        } else {
            rowsToReload.append(NSIndexPath(forRow: _currentSong, inSection:0))
        }
    }
    rowsToReload.append(NSIndexPath(forRow: btnCurrentPressed.tag, inSection:0))
    currentSong = stopCurrent ? nil : btnCurrentPressed.tag
    self.tableView.reloadRowsAtIndexPaths(rowsToReload, withRowAnimation: .None)
}

Answer 2

您不必每次都更改按钮的标题。你可以使用这样的东西：

func viewDidLoad {
    playButton.setTitle("Play", forState: UIControlState.Normal)
    playButton.setTitle("Stop", forState: UIControlState.Selected)
}

然后在您的回调方法中，您只需更改按钮的状态，文本也会更新：

func playAction(sender: UIButton!) {
    // Selected means the content is playing
    if !sender.selected {
        let track = dataOfTracks[sender.tag] as trackDoc
        let url = NSURL(string: track.data.url)

        player = AVPlayer(URL: url!)
        player.play()
    } else {
        player.pause()
    }
    // update the state of the button
    sender.selected = !sender.selected
}

我认为这是一个更干净的解决方案，因为您不再比较字符串来做出决定，并且您实际上是在使用按钮的二进制状态来跟踪内容的当前状态（这也是二进制的，播放或不播放）。

如果您有更多问题，我很乐意为您提供进一步的帮助，请告诉我。