날짜를 받아서 몇번째 주인지 표시 하는 것 Dart flutter

 

/* 날짜를 받아서 몇번째 주인지 표시 하는 것*/
  static String WeekCountHangul(DateTime cday) {
    var weekCount = cday.weekOfYear-cday.add(Duration(days: 1-cday.day)).weekOfYear+1;
    String weekCountHangul = "";
    switch (weekCount) {
      case 1: weekCountHangul = "첫째주"; break;
      case 2: weekCountHangul = "둘째주"; break;
      case 3: weekCountHangul = "세째주"; break;
      case 4: weekCountHangul = "네째주"; break;
      case 5: weekCountHangul = "다섯째주"; break;
      case 6: weekCountHangul = "여섯째주"; break;

    }
    return weekCountHangul;
  }

week_of_year: ^2.0.0
import 'package:week_of_year/week_of_year.dart';