如何制作倒数计时器？

嗨，我正在写一个记分牌UWP应用程序，我想知道如何使计时器背后的代码。 因为它是一个篮球记分牌，它有2个时钟，一个只有秒（射击时钟）和其他管理分钟和秒。 所以，我想知道是否有一种简单的方法可以在UWP中进行这种倒计时。

我刚刚发现了这个，但它不算下来：

private void stopwatch_Tapped(object sender, TappedRoutedEventArgs e) { if (_stopwatch.IsRunning) { _stopwatch.Stop(); _timer.Dispose(); } else { _stopwatch.Start(); _timer = new Timer(updateTime, null, (int)TimeSpan.FromMinutes(1).TotalMinutes, Timeout.Infinite); } } private async void updateTime(object state) { await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => { stopwatchLbl.Text = String.Format("{0:00}:{1:00}:{2:00}", _stopwatch.Elapsed.TotalMinutes, _stopwatch.Elapsed.TotalSeconds, _stopwatch.Elapsed.TotalMilliseconds / 10); //stopwatchLbl.Text = "00:00:00"; } ); } 

Answer 1

试试这个代码，我希望这会对你有所帮助:)

 internal class countDownTimer { public int enlapsedTime; private DispatcherTimer dispatch; public delegate void MyCallback(); public delegate void MyCallback2(int value); public MyCallback OnStartTime; public MyCallback OnStopTime; public MyCallback OnEndTime; public MyCallback2 OnCountTime; public countDownTimer() { Debug.WriteLine("StopWatch init"); enlapsedTime = 0; dispatch = new DispatcherTimer(); dispatch.Interval = new TimeSpan(0, 0, 1); dispatch.Tick += timer_Tick; } private void timer_Tick(object sender, object e) { enlapsedTime--; Debug.WriteLine(enlapsedTime); if (OnCountTime != null) OnCountTime(enlapsedTime); if (enlapsedTime < 0) { enlapsedTime = 0; dispatch.Stop(); if (OnEndTime != null) OnEndTime(); } } public void Start() { dispatch.Start(); if (OnStartTime != null) OnStartTime(); Debug.WriteLine("iniciar contador"); } public void Stop() { dispatch.Stop(); if (OnStopTime != null) OnStopTime(); Debug.WriteLine("parar contador"); } public bool IsEnabled { get { return dispatch.IsEnabled; } } } 

Answer 2

您可以使用我的NuGet包UWPHelper中的UWPHelper.Utilities.ThreadPoolTimer 。 您需要检查NuGet Package Manager中的Include pre-release复选框才能下载它。

我的ThreadPoolTimer是System.Threading.Timer的包装类，它的工作方式类似于DispatcherTimer但它在ThreadPool上运行，而不是在UI线程上运行。

 using UWPHelper.Utilities; // TimeSpan indicates the interval of the timer ThreadPoolTimer timer = new ThreadPoolTimer(TimeSpan.FromSeconds(1)); timer.Tick += OnTick; void OnTick(object sender, EventArgs e) { // Method invoked on Tick - every second in this scenario } // To start the timer timer.Start(); // To stop the timer timer.Stop();