Memory leak demo

main.dart

// Flutter code sample for Scaffold

// This example shows a [Scaffold] with an [AppBar], a [BottomAppBar] and a
// [FloatingActionButton]. The [body] is a [Text] placed in a [Center] in order
// to center the text within the [Scaffold]. The [FloatingActionButton] is
// centered and docked within the [BottomAppBar] using
// [FloatingActionButtonLocation.centerDocked]. The [FloatingActionButton] is
// connected to a callback that increments a counter.
//
// ![](https://flutter.github.io/assets-for-api-docs/assets/material/scaffold_bottom_app_bar.png)

import 'package:flutter/material.dart';
import 'package:syncfusion_flutter_gauges/gauges.dart';

void main() => runApp(MyApp());

/// This Widget is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: MyStatefulWidget(),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

  @override
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  int _count = 0;

  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Sample Code'),
      ),
      body: Center(
        child: Column(
          children: <Widget>[
            Text('You have pressed the button $_count times.'),
            SfRadialGauge(
              axes: <RadialAxis>[
                RadialAxis(
                  showLabels: false,
                  showTicks: false,
                  startAngle: 270,
                  endAngle: 270,
                  minimum: 0,
                  maximum: 100,
                  radiusFactor: 0.8,
                  axisLineStyle: AxisLineStyle(thicknessUnit: GaugeSizeUnit.factor, thickness: 0.15),
                  annotations: <GaugeAnnotation>[
                    GaugeAnnotation(
                        angle: 180,
                        widget: Row(
                          children: <Widget>[
                            Container(
                              child: Text('50'),
                            ),
                            Container(
                              child: Text(' / 100'),
                            )
                          ],
                        )),
                  ],
                  pointers: <GaugePointer>[
                    RangePointer(
                      value: 50,
                      cornerStyle: CornerStyle.bothCurve,
                      enableAnimation: true,
                      animationDuration: 1200,
                      animationType: AnimationType.ease,
                      sizeUnit: GaugeSizeUnit.factor,
                      gradient: const SweepGradient(colors: <Color>[Color(0xFF6A6EF6), Color(0xFFDB82F5)], stops: <double>[0.25, 0.75]),
                      color: const Color(0xFF00A8B5),
                      width: 0.15,
                    ),
                  ],
                ),
              ],
            )
          ],
        ),
      ),
      bottomNavigationBar: BottomAppBar(
        shape: const CircularNotchedRectangle(),
        child: Container(
          height: 50.0,
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => setState(() {
          _count++;
        }),
        tooltip: 'Increment Counter',
        child: Icon(Icons.add),
      ),
      floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
    );
  }
}