stopwatch

概述 在实际项目开发过程中，有时候需要在服务启动时进行一些业务初始化操作，这些操作只需要在服务启动后执行一次，那么通过Spring Boot如何实现该需求呢？ Spring Boot提供了ApplicationRunner和CommandLineRunner两种服务接口，这两种服务接口都可以实现上面的业务需求，本文将对这两种服务接口实现进行介绍。 ApplicationRunner与CommandLineRunner 异同点 相同点 两者均在服务启动完成后执行，并且只执行一次。 两者都能获取到应用的命令行参数。 两者触发执行的时间点是一致的。 不同点 虽然两者都是获取到应用的命令行参数，但是ApplicationRunner获取到的是封装后的ApplicationArguments对象，而CommandLine获取到的是ApplicationArguments中的sourceArgs属性（List<String>）,即原始参数字符串列表. 执行顺序 很多误认为CommandLineRunner会先于ApplicationRunner执行，但是实际上两者是一起触发执行的，可以阅读SpringApplication.class方法中的源码 1.SpringApplication.class中的run方法，会在执行完一些列初始化工作之后

So my app has 1 activity and 4 fragments and one of them has Chronometer to show how much time is passed. It works fine, but I have one issue that the chronometer keeps going back to 00:00 every time I move to another fragment and come back. I know it is because my startStopWatch() method is in OnCreateView, but is there any way to make it continue from where it stopped? Is it possible to use Bundle class to solve this? If so, how? Here is my code for Chronometer, all are in one fragment: public class FirstFragment extends Fragment { Chrhonometer chronometer; @Override public View onCreateView

So I have a stopwatch and all I want is for it to be display on a textblock. How can I do that? Create a TimerViewModel, that looks something like this: public class TimerViewModel : INotifyPropertyChanged { public TimerViewModel() { timer = new DispatcherTimer(); timer.Interval = TimeSpan.FromSeconds(1); timer.Tick += new EventHandler(timer_Tick); timer.Start(); startTime = DateTime.Now; } private DispatcherTimer timer; private DateTime startTime; public event PropertyChangedEventHandler PropertyChanged; public TimeSpan TimeFromStart { get { return DateTime.Now - startTime; } } private void

Given that the Stopwatch class in C# can use something like three different timers underneath e.g. System timer e.g. precision of approx +-10 ms depending on timer resolution that can be set with timeBeginPeriod it can be approx +-1 ms . Time Stamp Counter (TSC) e.g. with a tick frequency of 2.5MHz or 1 tick = 400 ns so ideally a precision of that. High Precision Event Timer (HPET) e.g. with a tick frequency of 25MHz or 1 tick = 40 ns so ideally a precision of that. how can we measure the observable precision of this? Precision being defined as Precision refers to the closeness of two or more

You can think of this like a really simple stopwatch. I'm trying to hack together a bash script that displays the elapsed time since a specified date and updates the output every second. First, Inside the script you'd specify a UNIX date: Fri Apr 14 14:00:00 EDT 2011 . This would be when the stopwatch starts. Now, when you run the script, you'd see... 06d:10h:37m:01s and a few seconds later you'd see... 06d:10h:37m:05s I'm not trying to have a new line printed for every second that elapses. The script should only have 1 line of output, and update it every second. Obviously you could quit the

Coming from my "answer" to question "Stopwatch in a Task seems to be additive across all tasks, want to measure just task interval" What are the possible differences between creating a new Stopwatch instance as: Stopwatch timer = System.Diagnostics.Stopwatch.StartNew(); with Stopwatch timer = new Stopwatch(); timer.Start(); Implied subquestion: Why was StartNew() method provided? StartNew , create new instance of the stop watch and starts it as well. Simple new is Stopwatch instantiation only. It doesn't start the Stopwatch. For your current code where you are creating a new instance and