flutter - 设置 CupertinoDatePicker minuteInterval : throws an exception. Flutter

Question

我在将 CupertinoDatePicker 的 minuteInterval: 属性设置为 30 时遇到问题。它应该是 60 的整数因子，所以 30 应该没问题。但我只能将它设置为 1 或 2，任何其他值都会引发此异常:

════════ Exception caught by widgets library ═══════════════════════════════════════════════════════
The following assertion was thrown building BlocBuilder<BookingBloc, BookingState>(dirty, state: _BlocBuilderBaseState<BookingBloc, BookingState>#c437f):
initial minute is not divisible by minute interval
'package:flutter/src/cupertino/date_picker.dart':
Failed assertion: line 269 pos 7: 'this.initialDateTime.minute % minuteInterval == 0'


Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
  https://github.com/flutter/flutter/issues/new?template=BUG.md

The relevant error-causing widget was: 
  BlocBuilder<BookingBloc, BookingState> file:///Volumes/archivi%20recuperati/Flutter%20apps%20/fixit_cloud_biking/lib/Screens/select_shop_booking_screen.dart:67:14
When the exception was thrown, this was the stack: 
#2      new CupertinoDatePicker (package:flutter/src/cupertino/date_picker.dart:269:7)
#3      _SelectShopBookingScreenState.build.<anonymous closure> (package:fixit_cloud_biking/Screens/select_shop_booking_screen.dart:132:36)
#4      BlocBuilder.build (package:flutter_bloc/src/bloc_builder.dart:90:50)
#5      _BlocBuilderBaseState.build (package:flutter_bloc/src/bloc_builder.dart:162:48)
#6      StatefulElement.build (package:flutter/src/widgets/framework.dart:4334:27)
...
════════════════════════════════════════════════════════════════════════════════════════════════════

是不是还有什么要设置的？

我是这样设置的。

非常感谢。

Expanded(
                          flex: 2,
                          child: Container(
                            padding: EdgeInsets.all(20),
                            color: Colors.transparent,
                            child: CupertinoDatePicker(
                                backgroundColor: Colors.transparent,
                                use24hFormat: true,
                                mode: CupertinoDatePickerMode.dateAndTime,
                                minuteInterval: 30,
                                onDateTimeChanged: (DateTime selected) {
                                  print('selected is $selected');
                                  BlocProvider.of<BookingBloc>(context).add(
                                      FindAvailableShopsForBooking(
                                          bookingStart:
                                              selected.millisecondsSinceEpoch,
                                          duration: widget.duration,
                                          cityDb: widget.cityDb,
                                          regionDb: widget.regionDb,
                                          countryDb: widget.countryDb));
                                }),
                          ),
                        ),

Answer 1

您应该更新两个参数:minuteInterval 和 initialDateTime。这是一个间隔为 30 分钟的示例:

              SizedBox(
                height: 200,
                child: CupertinoDatePicker(
                  minuteInterval: 30,
                  initialDateTime: DateTime.now().add(
                    Duration(minutes: 30 - DateTime.now().minute % 30),
                  ),
                  mode: CupertinoDatePickerMode.time,
                  use24hFormat: true,
                  onDateTimeChanged: (value) => setState(
                    () {
                      print(value);
                    },
                  ),
                ),
              ),