Question

我正在尝试获取特定星期数的日期范围。

以下是我的代码以获取相对于当前日期的星期数

final date = DateTime.now();
final startOfYear = new DateTime(date.year, 1, 1, 0, 0);
final firstMonday = startOfYear.weekday;
final daysInFirstWeek = 8 - firstMonday;
final diff = date.difference(startOfYear);
var weeks = ((diff.inDays - daysInFirstWeek) / 7).ceil();

if (daysInFirstWeek > 3) {
  weeks += 1;
}
print("Week Range $weeks");

我不了解我如何获取特定星期数的开始日期和结束日期。

任何帮助将不胜感激。

Answer 1

假设您的一周是从零开始的，则需要执行以下操作：

final date = new DateTime.now();
final startOfYear = new DateTime(date.year, 1, 1, 0, 0);
final firstMonday = startOfYear.weekday;
final daysInFirstWeek = 8 - firstMonday;
final diff = date.difference(startOfYear);
var weeks = ((diff.inDays - daysInFirstWeek) / 7).ceil();


main(){
  int week = weeks;
  print("Start Date for week $week: ${startOfYear.add(Duration(days: 7*week))}");
  print("End Date for week $week: ${startOfYear.add(Duration(days: 7*week+6))}");
}

Answer 2

要从星期数和年份中获取星期几和星期几。

DateTime getDateByWeekNumber({
  int weeknumber,
  int year,
  bool start
}) {
  //check if start == true retrun start date of week
  //else return end date
  var days = ((weeknumber - 1) * 7) + (start ? 0 : 6);
  return DateTime.utc(year, 1, days);
}

这符合ISO8601。您可以非常方便地选择星期几here

如何获取特定星期数的日期范围

2 个答案: