您好，我需要比较 2 个日期，例如开始日期和结束日期，如果我 select 是星期三，我需要这些日期之间的所有星期三

Question

I have a scenario where user selects a start date and end date and user also selects a specific day I need to show that specific day with date that occurs between them.

I tried the Intl package difference method but did not work

Answer 1

You can use this method. Takes the start and end date and also the weekday. Note, can pass in 3 as an int or 'DateTime.wednesday' as the argument.

Note, idea based on mirkancal's answer in this thread

List<DateTime> getAllDatesOfAWeekday(
    {required DateTime startDate,
    required DateTime endDate,
    required int weekday}) {
  List<DateTime> allDates = [];

  for (int i = 0; i <= endDate.difference(startDate).inDays; i++) {
    if (startDate.add(Duration(days: i)).weekday == weekday) {
      allDates.add(startDate.add(Duration(days: i)));
    }
  }
  return allDates;
}