Flutter 日期选择器showDatePicker

例图1

DateTime _dateTime=DateTime.now();
  String _showDatePicker(int selectIndex) {
    showDatePicker(
      context: context,
      initialDate: new DateTime.now(),
      firstDate: new DateTime.now().subtract(new Duration(days: 30)), // 减 30 天
      lastDate: new DateTime.now().add(new Duration(days: 30)),       // 加 30 天
    ).then((DateTime val) {
      print(val);   // 2020-02-24 00:00:00.000
      setState(() {
		// 需更新的参数
      });
    }).catchError((err) {
      print(err);
    });

例图2

import 'package:date_format/date_format.dart';
import 'package:flutter_cupertino_date_picker/flutter_cupertino_date_picker.dart';

 DateTime _dateTime=DateTime.now();
  String _showDatePicker() {
  	DatePicker.showDatePicker(
        context,
        pickerTheme: DateTimePickerTheme(
          showTitle: true,
          confirm: Text('确定', style: TextStyle(color: Colors.red)),
          cancel: Text('取消', style: TextStyle(color: Colors.cyan)),
        ),
        minDateTime: DateTime.parse("1980-05-21"),
//        maxDateTime: DateTime.parse("2020-05-21"),
        initialDateTime: _dateTime,
        dateFormat: "yyyy-MM-dd",
        //只包含年、月、日
//        dateFormat: 'yyyy年M月d日  EEE,H时:m分',
        pickerMode: DateTimePickerMode.datetime,
        locale: DateTimePickerLocale.zh_cn,
        onCancel: () {
          debugPrint("onCancel");
        },
        onConfirm: (dateTime, List<int> index) {
          setState(() {
//            _dateTime=dateTime;
          });
        }
    );
  }