Flutter DateTime日期转换

作者: Clover园 | 来源:发表于2020-05-20 00:23 被阅读0次

Flutter DateTime日期转换
Python 学习笔记12 - 常用内建模块
Python 中的日期和时间
Python datetime
C# 日期格式化常用
常用内置函数一
datetime
datetime
python3日期格式之间的互相转换
Python每日学习知识点

方法名称	说明
now()	命名构造，获取当前时间
millisecondsSinceEpoch	DateTime转时间戳
fromMillisecondsSinceEpoch	时间戳转DateTime
parse(string)	字符串转DateTime
isBefore(date)	时间比较---在之前
isAfter(date)	时间比较---在之后
isAtSameMomentAs(date)	时间比较---相等
compareTo(date)	大于返回1；等于返回0；小于返回-1
add(Duration)	时间增加
subtract(Duration)	时间减少
difference(date)	时间差两个时间相差小时数
timeZoneName	本地时区简码
timeZoneOffset	返回UTC与本地时差小时数
year、month、day、hour、minute、second、millisecond、microsecond	返回年、月、日、时、分、秒、毫秒、微妙
weekday	返回星期几

CalendarDatePicker 1.5版后面的日期选择
showDatePicker 弹出日期选择
showTimePicker 弹出时间选择

1.png

demo装了 date_format: ^1.0.8

import 'package:flutter/material.dart';
import 'package:date_format/date_format.dart';

class DatePickerPage extends StatefulWidget {
  DatePickerPage({Key key}) : super(key: key);
  @override
  _DatePickerPageState createState() => _DatePickerPageState();
}

class _DatePickerPageState extends State<DatePickerPage> {
  DateTime today = DateTime.now();
  var _time =
      TimeOfDay(hour: DateTime.now().hour, minute: DateTime.now().minute);
  // _showDatePicker() {
  //   showDatePicker(
  //           context: context,
  //           initialDate: today, //初始日期
  //           firstDate: DateTime(2020, 5, 5),
  //           lastDate: DateTime(2021, 5, 31)
  //   ).then((value) {
  //     setState(() {
  //        today = value;
  //     });
  //   });
  // }

  _showDatePicker() async {
    var _result = await showDatePicker(
        context: context,
        initialDate: today, //初始日期
        firstDate: DateTime(2020, 5, 5),
        lastDate: DateTime(2021, 5, 31));
    setState(() {
      today = _result != null ? _result : today;
    });
  }

  _showTimePicker() {
    showTimePicker(context: context, initialTime: _time).then((value) {
      setState(() {
        print(value);
        this._time = value;
          print(this._time);
      });
    });
  }

  @override
  void initState() {
    super.initState();
    print('当前时间是：$today');

    var date1 = today.millisecondsSinceEpoch;
    print('当前时间戳：$date1');

    var date2 = DateTime.fromMillisecondsSinceEpoch(date1);
    print('时间戳转日期：$date2');

    //拼接成date
    var dentistAppointment = new DateTime(2020, 5, 27, 17, 30, 20);
    print(dentistAppointment);

    // 字符串转date
    DateTime date3 = DateTime.parse("2019-07-29 15:32:41");
    print(date3);

    // 时间比较
    print(today.isBefore(date3)); // 在之前
    print(today.isAfter(date3)); // 在之后
    print(date3.isAtSameMomentAs(date3)); // 相同

    print(date3.compareTo(today)); // 大于返回1；等于返回0；小于返回-1。
    // print(DateTime.now().toString());
    // print(DateTime.now().toIso8601String());

    //时间增加
    var fiftyDaysFromNow = today.add(new Duration(days: 5));
    print('today加5天：$fiftyDaysFromNow');

    //时间减少
    DateTime fiftyDaysAgo = today.subtract(new Duration(days: 5));
    print('today减5天：$fiftyDaysAgo');

    //时间差 两个时间相差 小时数
    print('比较两个时间 差 小时数：${fiftyDaysFromNow.difference(fiftyDaysAgo)}');

    print('本地时区简码：${today.timeZoneName}');

    print('返回UTC与本地时差 小时数：${today.timeZoneOffset}');

    print(
        '获取年月日：${today.year}'); //month、day、hour、minute、second、millisecond、microsecond

    print('星期：${today.weekday}'); // 返回星期几
    print(formatDate(today, [yyyy, '-', mm, '-', dd])); //2020-05-19
    print(formatDate(
        DateTime(2050, 02, 21), [yyyy, '/', mm, '-', dd])); //2050/02-21
    print(formatDate(DateTime(1989, 02, 1, 15, 40, 10),
        [hh, ':', nn, ':', ss, ' ', am])); // 03:40:10 PM
    print(formatDate(DateTime(1989, 02, 1, 15, 40, 10),
        [HH, ':', nn, ':', ss, ' ', Z])); //15:40:10 GMT
    print(formatDate(DateTime(1989, 3, 2), [yy, '-', mm, '-w', W])); //89-03-w9
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(title: Text('日期组件 demo')),
        body: Column(children: <Widget>[
          Column(children: <Widget>[
            CalendarDatePicker(
                //自带的日期组件
                initialDate: today,
                onDateChanged: (date) {
                  setState(() {
                    today = date;
                  });
                },
                firstDate: DateTime(2020, 5, 5),
                lastDate: DateTime(2021, 5, 31)),
            Text('选择：${formatDate(today, [yyyy, '/', mm, '/', dd])}')
          ]),
          SizedBox(height: 30.0),
          Row(mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[
            Row(children: [
              InkWell(
                  child: Row(children: <Widget>[
                    Text(formatDate(today, [yyyy, '/', mm, '/', dd])),
                    Icon(Icons.arrow_drop_down)
                  ]),
                  onTap: () {
                    this._showDatePicker();
                  })
            ]),
            Row(mainAxisAlignment: MainAxisAlignment.center, children: [
              InkWell(
                  child: Row(children: <Widget>[
                    Text('${_time.format(context)}'),
                    Icon(Icons.arrow_drop_down)
                  ]),
                  onTap: () {
                    this._showTimePicker();
                  })
            ])
          ])
        ]));
  }
}