Flutter Format Time of Day 从时间选择器开始

Question

我正在尝试从我的颤振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，它将格式化选择的时间，但是当我运行我的代码时，我收到错误'flutter: type 'TimeOfDay' is not a subtype of type 'Widget'。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);

Answer 2

字符串时间 = _timePicked.format(context);