Question

我在UITableViewCell的子类中创建了一个计时器函数，它使用计时器更新自身的标签（标签文本）：

 func handleCountdown(){
    if timerIsRunning == false { //check if timer is NOT running, otherwise update timer 
        timerIsRunning = true
        startTime = activity.countdownValue
        runTimer()
    }
}

func runTimer() {
    timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: (#selector(self.updateTimer)), userInfo: nil, repeats: true)
}
@objc func updateTimer(){
    let hours = Int(startTime) / 3600
    let minutes = Int(startTime) / 60 % 60

    if startTime > 0 {
        startTime -= 1
        print("The start time for " + String(activity.name) + "is " + String(startTime))
        switch startTime {
        case 0:
            activity.isActive = false
            activity.timerIsRunning = false
            activity.countdownValue = 0
            timer.invalidate()
            activitiesRef = Database.database().reference().child("Users/\(userID)/Activities")
            activitiesRef.child(self.activity.id).setValue([ "id": self.activity.id,
                                                             "name": self.activity.name,
                                                             "isActive": self.activity.isActive,
                                                             "locString": self.activity.locationString,
                                                             "locLat": self.activity.locLat,
                                                             "locLong": self.activity.locLong,
                                                             "privacySetting": self.activity.privacySetting,
                                                             "timerIsRunning": self.activity.timerIsRunning,
                                                             "countdownValue": self.activity.countdownValue])
            returnToInactiveDelegate?.activeToInactive(data: activity)
        case 1..<60: //display seconds
            let count = String(Int(startTime))
            countdownTimer.text = count
            print("The start time for " + String(activity.name) + "is " + String(startTime))

            //countdownTimer.text = String(Int(startTime)) + "s"
        case 60..<3600: //display minutes
            print("The start time for " + String(activity.name) + "is " + String(startTime))

            countdownTimer.text = String(Int(minutes)) + "m"
        case 3600..<86400: // display hours and minutes
            print("The start time for " + String(activity.name) + "is " + String(startTime))

            countdownTimer.text = String(Int(hours)) + "h \(minutes)m"
        default:
            timer.invalidate()
            activity.countdownValue = 0
        }
    }

当计时器到达零时，委托函数删除相应的单元格并将其移动到表格视图中的不同部分，如下所示：

 func activeToInactive(data: Activity) {
    if let i = activeActivities.index(where: { $0.isActive == false }) {
        print("array index to remove: should be where it is NOT active = \(i)")
        activeActivities.remove(at: i)
    }
    inactiveActivities.insert(data, at: 0)
    self.tableView.reloadData()
}

最后，在表视图重新加载时，它会进行最后一次检查以确定计时器是否仍在运行（看它是否应该从初始启动时间启动计时器，或者不执行任何操作并让它处理倒计时）如下：

let inactiveCell = tableView.dequeueReusableCell(withIdentifier: inactiveIdentifer , for: indexPath) as! InactiveCell
    let activeCell = tableView.dequeueReusableCell(withIdentifier: activeIdentifier, for: indexPath) as! ActiveCell

    if indexPath.section == 0 && self.activeActivities.count != 0  {
        activeCell.name.text = self.activeActivities[indexPath.row].name
        activeCell.location.text = self.activeActivities[indexPath.row].locationString
        activeCell.activity = self.activeActivities[indexPath.row]
        activeCell.returnToInactiveDelegate = self
        if activeCell.activity.isActive == true && activeCell.timerIsRunning == false {
            activeCell.activity.countdownValue = self.activeActivities[indexPath.row].countdownValue
            print(String(self.activeActivities[indexPath.row].countdownValue))
            activeCell.handleCountdown()
        }
        activeCell.countdownTimer.text = String(self.activeActivities[indexPath.row].countdownValue)
        //activeCell.countdownTimer.text = self.activeActivities[indexPath.row].


        return activeCell

我遇到的问题是倒计时标签文本没有更新，尽管它在终端控制台中显示正确的输出。通过此示例我的错误是可重复的：有两个活动活动，其中倒计时功能相互独立。

activeActivity[0]运行为零，然后由ojbc func updateTimer中的case 0处理，并通过委托传递，然后将其从active中删除并将其移至inactive。剩下的一个（以前是activeActivity[1]，现在是activeActivity[0]）移动＆＃34; up＆＃34;在队列中，计时器根据终端日志继续运行，但countdownLabel.text卡在1s，尽管终端显示updateTimer的执行，并打印出应该在表格视图单元格中显示的正确开始时间。

UILabel表格视图上的文本标签和计时器功能问题刷新

0 个答案: