1、获取当前时间
var now = new DateTime.now();
print ("${now.year}-${now.month}-${now.day}");
print(now);//2022-02-07 04:12:18.125116
2、设置时间
var d =new DateTime(2022, 2, 7, 18, 37 , 26);
print(d);//2022-02-07 18:37:26.000
3、创建UTC时间
var ds = new DateTime.utc(2019, 10, 10, 9, 30);
print(ds);//2019-10-10 09:30:00.000Z
4、解析时间
var d1 = DateTime.parse('2018-10-10 09:30:36');
print(d1);//2020-10-10 09:30:36.000
var d2 = DateTime.parse('2018-10-10 09:30:30+0800');
print(d2);//2020-10-10 01:30:30.000Z
5、时间加减
var now = new DateTime.now();//2022-02-07 04:17:30.905388
print(now.add(new Duration(minutes: 10)));//加10分钟 2022-02-07 04:27:37.905388
print(now.add(new Duration(minutes: -10)));//减10分钟 2022-02-07 04:07:37.905388
print(now.add(new Duration(hours: 2)));//加2小时 2022-02-07 06:17:37.905388
print(now.add(new Duration(hours: -2)));//减2小时 2022-02-07 02:17:37.905388
6、 比较时间
var d3 = new DateTime(2019, 6, 20);
var d4 = new DateTime(2019, 7, 20);
var d5 = new DateTime(2019, 6, 20);
print(d3.isAfter(d4));//是否在d4之后 false
print(d3.isBefore(d4));//是否在d4之前 true
print(d3.isAtSameMomentAs(d5));//是否相同 true
7、计算时间差
var d6 = new DateTime(2019, 6, 19, 16 , 30);
var d7 = new DateTime(2019, 6, 20, 15, 20);
var difference = d7.difference(d6);
print([difference.inDays, difference.inHours,difference.inMinutes]);//d6与d7相差的天数与小时,分钟
8、时间戳
var now = new DateTime.now();
print(now.millisecondsSinceEpoch);//单位毫秒，13位时间戳 1644178922997
print(now.microsecondsSinceEpoch);//单位微秒，16位时间戳 1644178922997751
9、打印当前时间
var now = new DateTime.now();
// padLeft(int width,String sring)：如果字符串长度小于width，在左边填充sring
String timeStr="${now.year.toString()}-${now.month.toString().padLeft(2,'0')}-${now.day.toString().padLeft(2,'0')} ${now.hour.toString().padLeft(2, '0')}:${now.minute.toString().padLeft(2, '0')}:${now.second.toString().padLeft(2, '0')}";
print(timeStr);//2022-02-10 02:29:40
10、手机当前的时区
print('${DateTime.now().timeZoneName}');//CST
11、手机当前的时区的偏移量
print('${DateTime.now().timeZoneOffset}');//8:00:00.000000 缩写为+8.00
12、某年的某月有多少天
int _getDaysInMonth() {
return DateUtils.getDaysInMonth(_selectedYear, _selectedMonth);
}
13、某年某月的第一天是星期几
final weekday = DateTime(_selectedYear, _selectedMonth).weekday;
