如何使用其他类的Android Studio中的方法

Question

我有2个类DateDifference.java和Others.java我的DateDifference.java看起来像这样

public class DateDifference {
    public static void main(String[] args) {
        // Creates two calendars instances
        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();

        // Set the date for both of the calendar instance
        cal1.set(2006, Calendar.DECEMBER, 30);
        cal2.set(2007, Calendar.MAY, 3);

        // Get the represented date in milliseconds
        long millis1 = cal1.getTimeInMillis();
        long millis2 = cal2.getTimeInMillis();

        // Calculate difference in milliseconds
        long diff = millis2 - millis1;

        // Calculate difference in seconds
        long diffSeconds = diff / 1000;

        // Calculate difference in minutes
        long diffMinutes = diff / (60 * 1000);

        // Calculate difference in hours
        long diffHours = diff / (60 * 60 * 1000);

        // Calculate difference in days
        long diffDays = diff / (24 * 60 * 60 * 1000);

        System.out.println("In milliseconds: " + diff + " milliseconds.");
        System.out.println("In seconds: " + diffSeconds + " seconds.");
        System.out.println("In minutes: " + diffMinutes + " minutes.");
        System.out.println("In hours: " + diffHours + " hours.");
        System.out.println("In days: " + diffDays + " days.");
    }
}

我如何能够在others.java或所有其他类中始终打印出defdefnce？

Answer 1

如果我正确理解了您的问题，您想从其他类中调用DateDifference中的代码。您可以在DateDifference.java中创建一个静态函数，然后在其中放置所需的代码，然后从所需的类中调用DateDifference.funstionName（）。

Answer 2

如果要使用您拥有的参数在Others.java中调用方法，则可以仅使用其名称和“。”进行调用。

Others.whatever(millis1);

任何方法都必须为public和static。如果要从另一个方法调用变量，则可以将其公开]
public class DateDifference {
        public long millis1;
        public  long millis2;
        public  long diff;
        public  long diffSeconds;
        public  long diffMinutes;
        public  long diffHours;
        public  long diffDays;
    public static void main(String[] args) {
        // Creates two calendars instances
        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();

        // Set the date for both of the calendar instance
        cal1.set(2006, Calendar.DECEMBER, 30);
        cal2.set(2007, Calendar.MAY, 3);

        // Get the represented date in milliseconds
        millis1 = cal1.getTimeInMillis();
        millis2 = cal2.getTimeInMillis();

        // Calculate difference in milliseconds
        diff = millis2 - millis1;

        // Calculate difference in seconds
        diffSeconds = diff / 1000;

        // Calculate difference in minutes
        diffMinutes = diff / (60 * 1000);

        // Calculate difference in hours
        diffHours = diff / (60 * 60 * 1000);

        // Calculate difference in days
        diffDays = diff / (24 * 60 * 60 * 1000);

        System.out.println("In milliseconds: " + diff + " milliseconds.");
        System.out.println("In seconds: " + diffSeconds + " seconds.");
        System.out.println("In minutes: " + diffMinutes + " minutes.");
        System.out.println("In hours: " + diffHours + " hours.");
        System.out.println("In days: " + diffDays + " days.");
    }
}

访问例如mills1：
DateDifference.mills1;