addMonths method

DateTime addMonths(
  1. int monthDifference
)

增加月份

Implementation

DateTime addMonths(int monthDifference) {
  int yearDiff = monthDifference ~/ 12;
  final int monthDiff = monthDifference % 12;
  int month = this.month + monthDiff;
  if (month > 12) {
    yearDiff = yearDiff + 1;
    month = month - 12;
  }
  final int year = this.year + yearDiff;
  final int day = this.day - 1;
  return DateTime(year, month, day);
}