如何在Objective C中加载计数器形式的当前文本

Question

我是 iOS 新手，我在加载计数器时遇到问题。 我的代码是这样的

在

viewDidLoad()
{
    if (!_currentTimeInSeconds) {

           }_currentTimeInSeconds = 0 ;
     if (!_myTimer) {
            _myTimer = [self createTimer];
        }
}
- (NSTimer *)createTimer {
    return [NSTimer scheduledTimerWithTimeInterval:1.0
                                            target:self
                                          selector:@selector(timerTicked:)
                                          userInfo:nil
                                           repeats:YES];
}



- (NSString *)formattedTime:(int)totalSeconds
{
    int seconds = totalSeconds % 60;
    int minutes = (totalSeconds / 60) % 60;
    int hours = totalSeconds / 3600;

    return [NSString stringWithFormat:@"%02d:%02d:%02d",hours, minutes, seconds];
}
- (void)timerTicked:(NSTimer *)timer {

    _currentTimeInSeconds++;

    clockLabel.text = [self formattedTime:_currentTimeInSeconds];

}
-(void)updateTime
{
    NSDate *date= [NSDate date];
    NSDateFormatter *formatter1 = [[NSDateFormatter alloc]init]; //for hour and minute

    formatter1.dateFormat = @"hh:mm:ss";// use any format

    clockLabel.text = [formatter1 stringFromDate:date];
}

保存

 NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];
 Timmer=clockLabel.text;
 [defaults setValue:Timmer forKey:@"Timmer"];
 [defaults synchronize];

用于检索

 NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];
Timmer=[defaults objectForKey:@"Timmer"];
clockLabel.text=Timmer;

此代码从 0 开始设置值。 我需要从我离开计数的地方设置值。如何做到这一点？ 提前致谢！

Answer 1

如果您想在退出并重新启动应用程序后检索计数，那么您应该将值保存/存储到NSUserDefaults。

Answer 2

离开控制器时只需在 NSUserDefaults 中设置值。整个代码经过测试，它的工作完全正常。请参阅上面的评论视频。

var _currentTimeInSeconds : Int = Int()
var _myTimer : Timer = Timer()

override func viewDidLoad() {
        super.viewDidLoad()
        _currentTimeInSeconds = 0 ;
        _myTimer = self.createTimer()
 }

func createTimer()-> Timer {
        return Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerTicked), userInfo: nil, repeats: true)
}
func timerTicked(_ timer: Timer) {
    _currentTimeInSeconds += 1;
    label.text = self.formattedTime(self._currentTimeInSeconds)

}
func formattedTime(_ totalSeconds: Int) -> String {
    let seconds: Int = totalSeconds % 60
    let minutes: Int = (totalSeconds / 60) % 60
    let hours: Int = totalSeconds / 3600
    return String(format: "%02d:%02d:%02d", hours, minutes, seconds)
}
func updateTime() {
        let date = Date()
        let formatter1 = DateFormatter()
        //for hour and minute
        formatter1.dateFormat = "hh:mm:ss"
        // use any format
        label.text = formatter1.string(from: date)
}
override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(true)
        print(_currentTimeInSeconds)
        let defaults = UserDefaults.standard
        defaults.setValue(_currentTimeInSeconds, forKey: "Timmer")
        defaults.synchronize()
}
override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        let defaults = UserDefaults.standard
        if  (defaults.object(forKey: "Timmer") != nil){
            _currentTimeInSeconds = defaults.object(forKey: "Timmer") as! Int
            print(_currentTimeInSeconds)
        }
 }

快乐编码。

Answer 3

- (void)viewDidLoad {

    timeSec=[[NSString stringWithFormat:@"%ld",(long)[[NSUserDefaults standardUserDefaults]integerForKey:@"timeSec"]] intValue];
    timeMin=[[NSString stringWithFormat:@"%ld",(long)[[NSUserDefaults standardUserDefaults]integerForKey:@"timeMin"]] intValue];
    [self StartTimer];
}
-(void) StartTimer
{
    timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerTick:) userInfo:nil repeats:YES];
    [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
    self.lbl_timer.text=@"00:00";

}
- (void)timerTick:(NSTimer *)timer
{
    timeSec++;
    if (timeSec == 60)
    {

        timeSec = 0;
        timeMin++;
    }
    self.lbl_timer.text= [NSString stringWithFormat:@"%02d:%02d", timeMin, timeSec];;
}

当您回到屏幕时添加此代码。如返回按钮或关闭按钮操作

[timer invalidate];
[[NSUserDefaults standardUserDefaults]setInteger:timeSec forKey:@"timeSec"];
[[NSUserDefaults standardUserDefaults]setInteger:timeMin forKey:@"timeMin"];