从扑朔迷离的DateTime类中获得出乎意料的约会

Question

我正在尝试合并日期和时间的弦乐格式，以便我可以有两个时间戳的差异。

但是，当将日期作为" 2019年7月31日"one_answers" 5:07 pm"(以正确格式((在TodateTimeFormat方法中看到的正确格式(时，它将给我带来意外的日期，即2019--07-01 17：07：00.000，预期日期应为2019-07-31 17：07：00.000

我也尝试使用datetime.utc构造函数，但没有成功，以下是我的代码

import 'package:intl/intl.dart';
void main(){
  String dateOne = "31-July-2019";
  String timeOne = "5:07PM";
  String dateTwo = "01-Aug-2019";
  String timeTwo = "12:00AM";
  DateTime reminderDate = toDateTimeFormat(dateOne,timeOne);
  // 2019-07-01 17:07:00.000  which is wrong...,  EXPECTED --> 2019-07-31 17:07:00.000
  DateTime dueDate = toDateTimeFormat(dateTwo, timeTwo);
  bool value = isValidReminderDate(reminderDate, dueDate);
  // REMINDER DATE < DUE DATE SO RETURN TRUE ELSE FALSE...., EXPECTED --> TRUE
  print(value);
}
var monthsNames = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "July", "Aug", "Sept", "Oct", "Nov", "Dec"];
DateTime toDateTimeFormat(String date, String time){
  if(date != null && time != null){
    //date: 01-jan-2000 and time: "6:45PM"
    List<String> _parts = date.split("-");
    List<String> _timeParts =[];
      var dt = DateFormat("h:mma").parse(time);
      _timeParts = DateFormat('HH:mm').format(dt).split(":");
    DateTime dateTime =  DateTime(int.parse(_parts[2]),monthsNames.indexOf(_parts[1]),int.parse(_parts[0]), int.parse(_timeParts[0]), int.parse(_timeParts[1]) ,);
    // ALSO TRIED WITH DateTime.utc(int.parse(_parts[2]),monthsNames.indexOf(_parts[1]),int.parse(_parts[0]), int.parse(_timeParts[0]), int.parse(_timeParts[1]) ,);
    // but of no use...
    print("dateTime :: $dateTime");
    return dateTime;
  }
}
bool isValidReminderDate(DateTime reminderDate, DateTime dueDate){
  print('isValidReminderDate :: ${reminderDate.difference(dueDate).isNegative}');
  return reminderDate.difference(dueDate).isNegative;
}

Answer 1

您应该能够使用package:intl直接解析这些字符串(下面有一个警告(。

  var dateOne = "31-Jul-2019";
  var timeOne = "5:07PM";
  var dateTwo = "01-Aug-2019";
  var timeTwo = "12:00AM";
  var format = DateFormat("dd'-'MMM'-'yyyy hh:mma");
  var one = format.parse('$dateOne $timeOne');
  var two = format.parse('$dateTwo $timeTwo');
  print('$one $two ${two.difference(one)}');

打印2019-07-31 17:07:00.000 2019-08-01 00:00:00.000 6:53:00.000000

警告是您必须使用Jul而不是July，而Sep不是Sept，因为您在其他地方使用了3个字母缩写。