Question

我试图编写一个程序来显示一个显示分钟和秒的倒数计时器。我知道如何在几秒钟内完成，但我不确定如何在几分钟和几秒钟内完成倒计时。

例如，倒计时应如下所示：

2分59秒
  2分58秒
  2分57秒
  等等

到目前为止，这是我的代码：

import java.util.Scanner;

public class Test 
{
    public static void main(String[] args) throws InterruptedException 
    {
        Scanner scan = new Scanner(System.in);
        System.out.println("How much time (In Minutes) ?");
        int timet= scan.nextInt();
        long delay = timet * 1000;

        do
        {
            Thread.sleep(1000);
        System.out.println(timet / 1);
        timet = timet - 1;
            delay = delay - 1000;

        }
        while (delay != 0);
        System.out.println("Time's Up!");
    }
}

Answer 1

首先，您需要将timet乘以60以将分钟转换为秒（在下面更新）。您可以使用modulo（％）来获取剩余的秒数。请参阅我在“do”中添加的3行，按照您的描述以分钟和秒打印时间。我没有批评其余的代码。

import java.util.Scanner;

public class Test
{
  public static void main(String[] args) throws InterruptedException
  {
    Scanner scan = new Scanner(System.in);
    System.out.println("How much time (In Minutes) ?");
    int timet= scan.nextInt() * 60; // Convert to seconds
    long delay = timet * 1000;

    do
    {
      int minutes = timet / 60;
      int seconds = timet % 60;
      System.out.println(minutes +" minute(s), " + seconds + " second(s)");
      Thread.sleep(1000);
      timet = timet - 1;
      delay = delay - 1000;

    }
    while (delay != 0);
    System.out.println("Time's Up!");
  }
}

示例输出：

How much time (In Minutes) ?
5
5 minute(s), 0 second(s)
4 minute(s), 59 second(s)
4 minute(s), 58 second(s)
4 minute(s), 57 second(s)

Answer 2

如果我理解你的问题，你应该首先考虑如何格式化几秒钟（我会使用类似的东西），

private static String formatSeconds(long seconds) {
  return (seconds != 1) ? String.format(
      "%d seconds", seconds) : "1 second";
}

然后，您可以如何格式化分钟/分钟部分 -

static String formatTime(long millis) {
  long seconds = millis / 1000;
  if (seconds > 60) {
    long minutes = seconds / 60;
    seconds -= (minutes * 60);
    if (minutes > 1) {
      return String.format("%d minutes, %s",
          minutes, formatSeconds(seconds));
    } else {
      return String.format("1 minute, %s",
          formatSeconds(seconds));
    }
  }
  return formatSeconds(seconds);
}

最后，将它们组合在一起记录开始时的系统时间并计算应该何时结束，然后当前的倒计时时间是结束时间和当前时间之间的差异 - 也就是说，

public static void main(String[] args) {
  Scanner scan = new Scanner(System.in);
  System.out.println("How much time (In Minutes) ?");
  int minutes = scan.nextInt();
  long startTime = System.currentTimeMillis();
  long endTime = startTime + (minutes * 60 * 1000);
  while (System.currentTimeMillis() < endTime) {
    try {
      Thread.sleep(1000);
    } catch (InterruptedException e) {
    }
    System.out.println(formatTime(endTime
        - System.currentTimeMillis()));
  }
  System.out.println("Time's Up!");
}

倒数计时器在几分钟内

2 个答案: