我有一个DateTime的实例,我想将其格式化为字符串。我怎么做呢?我想把日期转换成一个字符串,类似于“2013-04-20”。
当前回答
这就给你提供了社交网络中的日期:[“今天”,“昨天”,“星期的哪一天”,等等。]
void main() {
DateTime now = new DateTime(2018,6,26);
print(date(now));
}
String date(DateTime tm) {
DateTime today = new DateTime.now();
Duration oneDay = new Duration(days: 1);
Duration twoDay = new Duration(days: 2);
Duration oneWeek = new Duration(days: 7);
String month;
switch (tm.month) {
case 1:
month = "january";
break;
case 2:
month = "february";
break;
case 3:
month = "march";
break;
case 4:
month = "april";
break;
case 5:
month = "may";
break;
case 6:
month = "june";
break;
case 7:
month = "july";
break;
case 8:
month = "august";
break;
case 9:
month = "september";
break;
case 10:
month = "october";
break;
case 11:
month = "november";
break;
case 12:
month = "december";
break;
}
Duration difference = today.difference(tm);
if (difference.compareTo(oneDay) < 1) {
return "today";
} else if (difference.compareTo(twoDay) < 1) {
return "yesterday";
} else if (difference.compareTo(oneWeek) < 1) {
switch (tm.weekday) {
case 1:
return "monday";
case 2:
return "tuesday";
case 3:
return "wednesday";
case 4:
return "thursday";
case 5:
return "friday";
case 6:
return "saturday";
case 7:
return "sunday";
}
} else if (tm.year == today.year) {
return '${tm.day} $month';
} else {
return '${tm.day} $month ${tm.year}';
}
}
其他回答
import 'package:intl/intl.dart';
main() {
var formattedDate = new DateTime.Format('yyyy-MM-dd').DateTime.now();
print(formattedDate); // something like 2020-04-16
}
有关更多详细信息,请参阅DateFormat文档
您可以使用intl包(安装程序)格式化日期。
对于en_US格式,它非常简单:
import 'package:intl/intl.dart';
main() {
final DateTime now = DateTime.now();
final DateFormat formatter = DateFormat('yyyy-MM-dd');
final String formatted = formatter.format(now);
print(formatted); // something like 2013-04-20
}
有许多格式化选项。从文档中可以看出:
ICU Name Skeleton
-------- --------
DAY d
ABBR_WEEKDAY E
WEEKDAY EEEE
ABBR_STANDALONE_MONTH LLL
STANDALONE_MONTH LLLL
NUM_MONTH M
NUM_MONTH_DAY Md
NUM_MONTH_WEEKDAY_DAY MEd
ABBR_MONTH MMM
ABBR_MONTH_DAY MMMd
ABBR_MONTH_WEEKDAY_DAY MMMEd
MONTH MMMM
MONTH_DAY MMMMd
MONTH_WEEKDAY_DAY MMMMEEEEd
ABBR_QUARTER QQQ
QUARTER QQQQ
YEAR y
YEAR_NUM_MONTH yM
YEAR_NUM_MONTH_DAY yMd
YEAR_NUM_MONTH_WEEKDAY_DAY yMEd
YEAR_ABBR_MONTH yMMM
YEAR_ABBR_MONTH_DAY yMMMd
YEAR_ABBR_MONTH_WEEKDAY_DAY yMMMEd
YEAR_MONTH yMMMM
YEAR_MONTH_DAY yMMMMd
YEAR_MONTH_WEEKDAY_DAY yMMMMEEEEd
YEAR_ABBR_QUARTER yQQQ
YEAR_QUARTER yQQQQ
HOUR24 H
HOUR24_MINUTE Hm
HOUR24_MINUTE_SECOND Hms
HOUR j
HOUR_MINUTE jm
HOUR_MINUTE_SECOND jms
HOUR_MINUTE_GENERIC_TZ jmv
HOUR_MINUTE_TZ jmz
HOUR_GENERIC_TZ jv
HOUR_TZ jz
MINUTE m
MINUTE_SECOND ms
SECOND s
对于非en_us日期,需要显式地加载语言环境。更多信息请参阅DateFormat文档。date_symbol_data_local。Dart包含每个国家/语言的所有格式,如果您想更深入地了解的话。
可以使用intl包格式化flutter中的日期。
void main() {
final DateTime now = DateTime.now();
final DateFormat format = DateFormat('yyyy-MM-dd');
final String formatted = format.format(now);
// 2021-03-02
}
或者可以使用date_format包来格式化flutter中的日期。
import 'package:date_format/date_format.dart';
final formattedStr = formatDate(DateTime.now(), [dd, '-', mm, '-', yyyy]);
//02-03-2021
处理年度季度,从字符串到日期时间,我没有找到合适的解决方案,所以做了这个:
List<String> dateAsList = 'Q1 2001'.split(' ');
DateTime dateTime = DateTime.now();
String quarter = dateAsList[0];
int year = int.parse(dateAsList[1]);
switch(quarter) {
case "Q1": dateTime = DateTime(year, 1);
break;
case "Q2": dateTime = DateTime(year, 4);
break;
case "Q3": dateTime = DateTime(year, 7);
break;
case "Q4": dateTime = DateTime(year, 10);
break;
}
main() {
final String pattern = 'yyyy-MM-dd';
final String formatted = DateFormat(pattern).format(DateTime.now());
print(formatted);
}
更改yyyy-MM-dd字符串可以更改日期格式。我用这个模式字符串做了一个应用程序。
你可以在我的应用程序中实验字符串格式。 https://biplobsd.github.io/EpochConverterApp
在这里你可以看到我如何编辑模式和这个效果显示在顶部