Flutter Format Time of Day 从时间选择器开始

Question

我正在尝试从我的 flutter 应用程序中的时间选择器中格式化选定的时间。我不知道为什么，但事实证明这比它应该的要困难得多。我想要达到的最终结果是小时:分钟或下午 5:00。用户从时间选择器小部件中选择时间后，这将显示在框容器中。我有一个名为“timeFormater()”的方法，它可以格式化选择的时间，但我收到错误 'flutter: 'TimeOfDay' 类型不是 'Widget' 类型的子类型 当我运行我的代码时。是否有更简单的方法/方法来格式化 TimeOfDay()？

我的代码:

      import 'package:flutter/material.dart';
    import 'package:flutter/cupertino.dart';
    import 'package:intl/intl.dart';
    import 'package:auto_size_text/auto_size_text.dart';
    import 'dart:io' show Platform;

    class DateTimePicker extends StatefulWidget {
      @override
      _DateTimePickerState createState() => _DateTimePickerState();
    }

    class _DateTimePickerState extends State<DateTimePicker> {
      DateTime _date = new DateTime.now();
      TimeOfDay _time = new TimeOfDay.now();
      Duration initialtimer = new Duration();
      DateTime _datePicked;
      TimeOfDay _timePicked;


      @override
      void initState() {
       // timeController.addListener(_time);

      }

      @override
      Widget build(BuildContext context) {
        return Container(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: <Widget>[
              Row(
                mainAxisAlignment: MainAxisAlignment.start,
                // mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  dateContainer(),
                  timeContainer()
                ],
              ),
              Row(
                mainAxisAlignment: MainAxisAlignment.start,
                children: <Widget>[
                  customDatePicker(context),
                  customTimePicker(context)
                ],
              ),
            ],
          ),
        );
      }
 Widget customTimePicker(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(left: 12.0),
      child: FlatButton(
          child: Text('Time', style: TextStyle(
              color: Colors.white
          ),),
          color: Colors.deepOrange,
          onPressed: () => _selectedTime(context)
      ),
    );
  }
 Future<Null> _selectedTime(BuildContext context) async {
    _timePicked = await showTimePicker(
        context: context,
        initialTime: _time);

    if (_timePicked != null) {
      setState(() {
        _time = _timePicked;
      });
    }
  }
 Widget timeContainer() {
    return Container(
      width: 100,
      height: 100,
      child: Padding(
          padding: const EdgeInsets.only(left: 16.0, top: 16.0,bottom: 16.0),
          child: Container(
            decoration: BoxDecoration(
              border: Border.all(
                width: .5,
                color: Colors.black
              )
            ),
            child: timeFormater(),
          )
      ),
    );
  }

  Widget timeFormater() {
    return Column(
      children: <Widget>[
        SizedBox(
          height: 20.0,
        ),
        _timePicked != null
            ? TimeOfDay(hour: _timePicked.hour, minute: _timePicked.minute)
            : SizedBox(
          width: 0.0,
          height: 0.0,
        ),
      ],
    );
  }
}

错误信息:

flutter: ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
flutter: The following assertion was thrown building DateTimePicker(dirty, dependencies: [_InheritedTheme,
flutter: _LocalizationsScope-[GlobalKey#6c45d]], state: _DateTimePickerState#7eeb8):
flutter: type 'TimeOfDay' is not a subtype of type 'Widget'
flutter:
flutter: Either the assertion indicates an error in the framework itself, or we should provide substantially
flutter: more information in this error message to help you determine and fix the underlying cause.
flutter: In either case, please report this assertion by filing a bug on GitHub:
flutter:   https://github.com/flutter/flutter/issues/new?template=BUG.md
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #0      _DateTimePickerState.timeFormater (package:rallie_app/utils/custom_date_timer.dart:176:13)
flutter: #1      _DateTimePickerState.timeContainer (package:rallie_app/utils/custom_date_timer.dart:163:20)
flutter: #2      _DateTimePickerState.build (package:rallie_app/utils/custom_date_timer.dart:37:15)
flutter: #3      StatefulElement.build (package:flutter/src/widgets/framework.dart:3830:27)
flutter: #4      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3741:15)
flutter: #5      Element.rebuild (package:flutter/src/widgets/framework.dart:3564:5)
flutter: #6      BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2277:33)
flutter: #7      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:700:20)
flutter: #8      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:275:5)
flutter: #9      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
flutter: #10     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
flutter: #11     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:842:5)
flutter: #15     _invoke (dart:ui/hooks.dart:209:10)
flutter: #16     _drawFrame (dart:ui/hooks.dart:168:3)
flutter: (elided 3 frames from package dart:async)

Answer 1

这将为您正确格式化 TimeOfDay:

final localizations = MaterialLocalizations.of(context);
final formattedTimeOfDay = localizations.formatTimeOfDay(timeOfDay);