如何计算android中两个日期之间的周数？我做过类似的事情
FormBuilder
但是，当两个日期在不同年份时，这不起作用。如何实现解决方案以使其在不同年份中发挥作用？
修改
我尝试过使用jodatime进行以下操作
FormControl这几乎可行，但出于某种原因，它认为本周的开始是星期四。我希望本周开始时间为周一，以便周一至周六返回0（同一周），但周六至周日将返回1（不同周）
答案 0 :(得分：1)
public int getWeekDifference(long fromDateInMills, long toDateInMills) {
int weeks = Weeks.weeksBetween(new DateTime(fromDateInMills), new DateTime(toDateInMills)).getWeeks();
// when we select any future date than week difference comes in negative so
// just interchange millisecond You will get week difference in positive
if (weeks < 0) {
weeks = Weeks.weeksBetween(new DateTime(toDateInMills), new DateTime(fromDateInMills)).getWeeks();
}
return weeks;
}
答案 1 :(得分：1)
这里有些答案给出了错误的结果，有些需要额外的库。我设法想出了一种使用标准 Calendar API 计算周差的方法。
它可以正确处理 2000-01-01 to 2000-12-31 之类的边缘情况（54 周意味着相差 53）。
public static int getWeeksBetween(final Date start, final Date end) {
final Calendar c1 = Calendar.getInstance(Locale.US);
final Calendar c2 = Calendar.getInstance(Locale.US);
// Skip time part! Not sure if this is needed, but I wanted clean dates.
CalendarUtils.setDateWithNoTime(c1, start);
CalendarUtils.setDateWithNoTime(c2, end);
CalendarUtils.goToFirstDayOfWeek(c1);
CalendarUtils.goToFirstDayOfWeek(c2);
int weeks = 0;
while (c1.compareTo(c2) < 0) {
c1.add(Calendar.WEEK_OF_YEAR, 1);
weeks++;
}
return weeks;
}
还有一些辅助方法：
public static int goToFirstDayOfWeek(final Calendar calendar) {
final int firstDayOfWeek = calendar.getFirstDayOfWeek();
calendar.set(Calendar.DAY_OF_WEEK, firstDayOfWeek);
return firstDayOfWeek;
}
public static void setDateWithNoTime(final Calendar calendar, final Date date) {
calendar.setTime(date);
clearTime(calendar);
}
public static void clearTime(final Calendar calendar) {
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
}
答案 2 :(得分：0)
在不使用JodaTime的情况下，我想出了以下解决方案来计算周数：
private fun calculateNumberOfWeeks() {
val calendarFrom = Calendar.getInstance()
calendarFrom.set(Calendar.HOUR_OF_DAY, 0)
calendarFrom.set(Calendar.MINUTE, 0)
calendarFrom.set(Calendar.SECOND, 0)
calendarFrom.set(Calendar.MILLISECOND, 0)
val calendarTo = Calendar.getInstance()
calendarTo.add(Calendar.MONTH, months)
calendarTo.set(Calendar.HOUR_OF_DAY, 0)
calendarTo.set(Calendar.MINUTE, 0)
calendarTo.set(Calendar.SECOND, 0)
calendarTo.set(Calendar.MILLISECOND, 0)
var weeks = -1
while (calendarFrom.timeInMillis < calendarTo.timeInMillis) {
calendarFrom.add(Calendar.DATE, 7)
weeks++
Log.d(Constants.LOG_TAG, "weeks $weeks")
}
}
答案 3 :(得分：0)
我建议您不要尝试以周为单位计算差异，而应尝试以天为单位查找差异，然后将结果除以7。
所以应该是几周=（daysBetweenDates / 7）
答案 4 :(得分：0)
使用Java 8
公共无效week_between_two_dates_in_java_with_java8（）{
var res = await getFromAPI();
setState(() {
listToPopulate = res;
});
}
或使用joda时间api
LocalDate startDate = LocalDate.of(2005, Month.JANUARY, 1);
LocalDate endDate = LocalDate.of(2006, Month.JANUARY, 1);
long weeksInYear = ChronoUnit.WEEKS.between(startDate, endDate);
答案 5 :(得分：0)
那种只用数学的低技术解决方案呢？
每个日期都有Week_OF_YEAR。还有每个的YEAR编号。 将每个Year数字乘以52，将其添加到WEEK_OF_YEAR，然后减去两个数字。 例如.... 2018第50周 至 2019一周2
2018 * 52 = 104936 + 50周= 104986
2019 * 52 = 104988 + 2周= 104990
104990-104986 = 4周
答案 6 :(得分：0)
另一种替代解决方案。我的基本概念是：
Java 示例：
public class Main {
public static void main(String[] args) {
Calendar Monday = Calendar.getInstance();
Monday.set(2020, 11, 28, 12, 34, 56); // 2020-12-28T12:34:56
Calendar Saturday = Calendar.getInstance();
Saturday.set(2021, 0, 2, 21, 43, 57); // 2021-01-02T21:43:57
Calendar Sunday = Calendar.getInstance();
Sunday.set(2021, 0, 3, 0, 1, 2); // 2021-01-03T00:01:02
Calendar NextMonday = Calendar.getInstance();
NextMonday.set(2021, 0, 4, 1, 23, 45); // 2021-01-04T01:23:45
System.out.println(String.format(": %d week(s)", weeksTouched(Monday, Sunday)));
System.out.println(String.format(": %d week(s)", weeksTouched(Saturday, Sunday)));
System.out.println(String.format(": %d week(s)", weeksTouched(Sunday, NextMonday)));
}
public static int weeksTouched(Calendar fromDate, Calendar toDate){
System.out.print(String.format("%s -> %s", fromDate.getTime(), toDate.getTime()));
return (int) (
(trimToMonday(toDate).getTimeInMillis() - trimToMonday(fromDate).getTimeInMillis())
/ (1000 * 60 * 60 * 24 * 7)
);
}
private static Calendar trimToMonday(Calendar input) {
Calendar output = (Calendar) input.clone();
switch (output.get(Calendar.DAY_OF_WEEK)) {
case Calendar.TUESDAY:
output.add(Calendar.DAY_OF_MONTH, -1);
break;
case Calendar.WEDNESDAY:
output.add(Calendar.DAY_OF_MONTH, -2);
break;
case Calendar.THURSDAY:
output.add(Calendar.DAY_OF_MONTH, -3);
break;
case Calendar.FRIDAY:
output.add(Calendar.DAY_OF_MONTH, -4);
break;
case Calendar.SATURDAY:
output.add(Calendar.DAY_OF_MONTH, -5);
break;
case Calendar.SUNDAY:
output.add(Calendar.DAY_OF_MONTH, -6);
break;
}
output.set(Calendar.HOUR_OF_DAY, 0);
output.set(Calendar.MINUTE, 0);
output.set(Calendar.SECOND, 0);
output.set(Calendar.MILLISECOND, 0);
return output;
}
}
输出：
Mon Dec 28 12:34:56 JST 2020 -> Sun Jan 03 00:01:02 JST 2021: 0 week(s)
Sat Jan 02 21:43:57 JST 2021 -> Sun Jan 03 00:01:02 JST 2021: 0 week(s)
Sun Jan 03 00:01:02 JST 2021 -> Mon Jan 04 01:23:45 JST 2021: 1 week(s)
答案 7 :(得分：-1)
这将为您提供两个星期的b / w两个星期。
public void getNoOfWeek()
{
Calendar date1 = Calendar.getInstance();
Calendar date2 = Calendar.getInstance();
date1.clear();
date1.set(2015, 12, 29); // set date 1 (yyyy,mm,dd)
date2.clear();
date2.set(2016, 02, 7); //set date 2 (yyyy,mm,dd)
long diff = date2.getTimeInMillis() - date1.getTimeInMillis();
float dayCount = (float) diff / (24 * 60 * 60 * 1000);
int week = (int) (dayCount / 7);
System.out.println(week);
}