cupertinoTimepicker 在颤振中没有正确显示

Question

cupertinoTimepicker 在颤振中没有正确显示

我编写了 cupertinoTimerpicker 代码，但无法正确显示

在我看来，我混合了一些功能，因此无法看到这个cupertinoTimePicker。

我该怎么办？

class CountDownTimer extends StatefulWidget {
  @override
  _CountDownTimerState createState() => _CountDownTimerState();
}


class _CountDownTimerState extends State<CountDownTimer>
    with TickerProviderStateMixin {

  AnimationController controller;
  Duration initialtimer = new Duration();
  int selectitem = 1;


  String get timerString {
    Duration duration = controller.duration * controller.value;
    return '${duration.inMinutes}:${(duration.inSeconds % 60).toString().padLeft(2, '0')}';
  }

  @override
  void initState() {
    super.initState();
    controller = AnimationController(
      vsync: this,
      duration: Duration(seconds: 600),
    );
  }

  Widget timePicker() {
    return CupertinoTimerPicker(
      mode: CupertinoTimerPickerMode.hms,
      minuteInterval: 1,
      secondInterval: 1,
      initialTimerDuration: initialtimer,
      onTimerDurationChanged: (Duration changedtimer) {
        setState(() {
          initialtimer = changedtimer;
          time =
              (changedtimer.inMinutes % 60).toString() +
              ' mins ' +
              (changedtimer.inSeconds % 60).toString() +
              ' secs';
        });
      },
    );
  }

  Future<void> bottomSheet(BuildContext context, Widget child,
      {double height}) {
    return showModalBottomSheet(
        isScrollControlled: false,
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.only(
                topLeft: Radius.circular(13), topRight: Radius.circular(13))),
        backgroundColor: Colors.white,
        context: context,
        builder: (context) => Container(
            height: height ?? MediaQuery.of(context).size.height / 3,
            child: child));
  }

  Widget button(String text, {Function onPressed, Color color}) {
    return Container(
      width: 200,
      height: 50,
      margin: EdgeInsets.symmetric(vertical: 5),
      color: color ?? Colors.redAccent,
      child: MaterialButton(
          child: Text(
            '$text',
            style: TextStyle(color: Colors.white),
          ),
          onPressed: onPressed),
    );
  }

  String time;

  @override
  Widget build(BuildContext context) {
    ThemeData themeData = Theme.of(context);
    return Scaffold(
      backgroundColor: Colors.white10,
      body: AnimatedBuilder(
          animation: controller,
          builder: (context, child) {
            return Stack(
              children: <Widget>[
                Align(
                  alignment: Alignment.bottomCenter,
                  child:
                  Container(
                    color: Colors.amber,
                    height:
                    controller.value * MediaQuery.of(context).size.height,
                  ),
                ),
                Padding(
                  padding: EdgeInsets.all(8.0),
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: <Widget>[
                      Expanded(
                        child: Align(
                          alignment: FractionalOffset.center,
                          child: AspectRatio(
                            aspectRatio: 1.0,
                            child: Stack(
                              children: <Widget>[
                                Positioned.fill(
                                  child: CustomPaint(
                                      painter: CustomTimerPainter(
                                        animation: controller,
                                        backgroundColor: Colors.white,
                                        color: themeData.indicatorColor,
                                      )),
                                ),
                                Align(
                                  alignment: FractionalOffset.center,
                                  child: Column(
                                    mainAxisAlignment:
                                    MainAxisAlignment.spaceEvenly,
                                    crossAxisAlignment:
                                    CrossAxisAlignment.center,
                                    children: <Widget>[
                                      Text(
                                        "Count Down Timer",
                                        style: TextStyle(
                                            fontSize: 20.0,
                                            color: Colors.white),
                                      ),
                                      Text(
                                        timerString,
                                        style: TextStyle(
                                            fontSize: 112.0,
                                            color: Colors.white),
                                      ),
                                    ],
                                  ),
                                ),
                              ],
                            ),
                          ),
                        ),
                      ),
                      AnimatedBuilder(
                          animation: controller,
                          builder: (context, child) {

                            return Column(

                              children: [

                                FloatingActionButton.extended(
                                    onPressed: () {
                                      if (controller.isAnimating)
                                        controller.stop();
                                      else {
                                        controller.reverse(
                                            from: controller.value == 0.0
                                                ? 1.0
                                                : controller.value);
                                      }
                                    },
                                    icon: Icon(controller.isAnimating
                                        ? Icons.pause
                                        : Icons.play_arrow),
                                    label: Text(
                                        controller.isAnimating ? "Pause" : "Play")),

                                button(
                                  "Cupertino Timer Picker",
                                  color: Colors.green,
                                  onPressed: () {
                                    bottomSheet(context, timePicker());
                                  },
                                ),
                                time == null ? Container() : Text('$time'),
                              ],

                            );
                          }),

                    ],
                  ),
                ),
              ],
            );
          }),
    );
  }

我指的是这个页面 https://gist.github.com/maheshmnj/f35813e62ae1a24cbd3acc71f797701d