dart时间处理的几个方法

new DateTime.now();

new DateTime(2020, 11, 11, 12, 37 , 36);

DateTime.parse(‘2018-10-10 09:30:36‘);

// 加10分钟
now.add(new Duration(minutes: 10))

// 减2小时
now.add(new Duration(hours: -2))

var d3 = new DateTime(2019, 6, 20);
var d4 = new DateTime(2019, 7, 20);
var d5 = new DateTime(2019, 6, 20);

print(d3.isAfter(d4));//是否在d4之后 false
print(d3.isBefore(d4));//是否在d4之前 true 
print(d3.isAtSameMomentAs(d5));//是否相同 true

var d6 = new DateTime(2019, 6, 19, 16 , 30);
var d7 = new DateTime(2019, 6, 20, 15, 20);
var difference = d7.difference(d6);
print([difference.inDays, difference.inHours,difference.inMinutes]);//d6与d7相差的天数与小时,分钟 [0, 22, 1370]

print(now.millisecondsSinceEpoch);//单位毫秒，13位时间戳  1561021145560
print(now.microsecondsSinceEpoch);//单位微秒，16位时间戳  1561021145560543

  String get publishTime {
    var now = new DateTime.now();
    var longTime = this.toString().length < 13 ? this * 1000 : this;
    var time = new DateTime.fromMillisecondsSinceEpoch(longTime);
    var difference = now.difference(time);
    int days = difference.inDays;
    int hours = difference.inHours;
    int minutes = difference.inMinutes;
    String result = ‘‘;
    if (days > 3) {
      bool isNowYear = now.year == time.year;
      var pattern = isNowYear ? ‘MM-dd‘ : ‘yyyy-MM-dd‘;
      result = new DateFormat(pattern).format(time);
    } else if (days > 0) {
      result = ‘$days天前‘;
    } else if (hours > 0) {
      result = ‘$hours小时前‘;
    } else if (minutes > 0) {
      result = ‘$minutes分钟前‘;
    } else {
      result = ‘刚刚‘;
    }
    return result;
  }