This is what it shows in terminal

59:48: Error: The method 'CustomTimerPainter' isn't defined for the class '_CountDownTimerState'.

• '_CountDownTimerState' is from 'package:braintrinig/pages/Countdown_timer.dart' ('lib/pages/Countdown_timer.dart'). Try correcting the name to the name of an existing method, or defining a method named 'CustomTimerPainter'. painter: CustomTimerPainter(

How to solve this issue?

This is my code:

import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';
class CountDownTimer extends StatefulWidget {
  @override
  _CountDownTimerState createState() => _CountDownTimerState();
}

class _CountDownTimerState extends State<CountDownTimer>
    with TickerProviderStateMixin {
  late AnimationController controller;

  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: 5),
    );
  }

  @override
  Widget build(BuildContext context) {
    ThemeData themeData = Theme.of(context);
    return Scaffold(
      backgroundColor: Colors.white10,
      body:
      Container(
        color: Colors.amber,
        height: controller.value * MediaQuery.of(context).size.height,
        child: 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 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"));
                            }),
                      ],
                    ),
                  ),
                ],
              );
            }),
      ),
    );
  }
}

CodePudding user response：

The CustomeTimerPainter is a custom widget that someone has already written in your taken example,

You may please check those examples, or you can use the sample below.

class CustomTimerPainter extends CustomPainter {
  CustomTimerPainter({
    this.animation,
    this.backgroundColor,
    this.color,
  }) : super(repaint: animation);

  final Animation<double> animation;
  final Color backgroundColor, color;

  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()
      ..color = backgroundColor
      ..strokeWidth = 10.0
      ..strokeCap = StrokeCap.butt
      ..style = PaintingStyle.stroke;

    canvas.drawCircle(size.center(Offset.zero), size.width / 2.0, paint);
    paint.color = color;
    double progress = (1.0 - animation.value) * 2 * math.pi;
    canvas.drawArc(Offset.zero & size, math.pi * 1.5, -progress, false, paint);
  }

  @override
  bool shouldRepaint(CustomTimerPainter old) {
    return animation.value != old.animation.value ||
        color != old.color ||
        backgroundColor != old.backgroundColor;
  }
}

CodePudding user response：

It checked that "CustomTimerPainter" is from circular_countdown_timer library. After you add this library, the problem you mentioned will be resolved.

I pasted your code to my project and install "circular_countdown_timer", I didn't see any error right now.

1. Add circular_countdown_timer in your pubspec.yaml => get => update.

dependencies:
  circular_countdown_timer: ^0.2.2

2. Import this library into your dart file

import 'package:circular_countdown_timer/custom_timer_painter.dart';