Android Java:如何减去两次? [英] Android Java : How to subtract two times?

问题描述

我在我的项目中使用了某种秒表并且我有

I use some kind of stopwatch in my project and I have

start time ex: 18:40:10 h
stop time  ex: 19:05:15 h

我需要这两个值的结果，例如 final time = stop - start

I need a result from those two values like final time = stop - start

我找到了一些例子，但它们都非常令人困惑.

I found some examples but they all are very confusing .

有什么简单的解决方法吗?

Is there any simple solution ?

推荐答案

如果您有字符串，您需要使用 java.text.SimpleDateFormat 将它们解析为 java.util.Date.类似的东西:

If you have strings you need to parse them into a java.util.Date using java.text.SimpleDateFormat. Something like:

        java.text.DateFormat df = new java.text.SimpleDateFormat("hh:mm:ss");
        java.util.Date date1 = df.parse("18:40:10");
        java.util.Date date2 = df.parse("19:05:15");
        long diff = date2.getTime() - date1.getTime();

这里的 diff 是 18:40:10 和 19:05:15 之间经过的毫秒数.

Here diff is the number of milliseconds elapsed between 18:40:10 and 19:05:15.

编辑 1:

在网上找到了一个方法(在 http://www.javaworld.com/javaworld/jw-03-2001/jw-0330-time.html?page=2):

Found a method online for this (at http://www.javaworld.com/javaworld/jw-03-2001/jw-0330-time.html?page=2):

  int timeInSeconds = diff / 1000;
  int hours, minutes, seconds;
  hours = timeInSeconds / 3600;
  timeInSeconds = timeInSeconds - (hours * 3600);
  minutes = timeInSeconds / 60;
  timeInSeconds = timeInSeconds - (minutes * 60);
  seconds = timeInSeconds;

编辑 2:

如果你想要它作为一个字符串(这是一种草率的方式，但它有效):

If you want it as a string (this is a sloppy way, but it works):

String diffTime = (hours<10 ? "0" + hours : hours) + ":" + (minutes < 10 ? "0" + minutes : minutes) + ":" + (seconds < 10 ? "0" + seconds : seconds) + " h";

编辑 3:

如果你想要毫秒就这样做

If you want the milliseconds just do this

long timeMS = diff % 1000;

然后您可以将其除以 1000 以获得秒的小数部分.

You can then divide that by 1000 to get the fractional part of your seconds.

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