main.dart

import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'FlChart Demo',
      showPerformanceOverlay: false,
      theme: ThemeData(
        primaryColor: const Color(0xff262545),
        primaryColorDark: const Color(0xff201f39),
        brightness: Brightness.dark,
      ),
      home: Scaffold(
        body: Center(
          child: AspectRatio(
            aspectRatio: 1.0,
            child: BarChart(
              BarChartData(
                barGroups: [
                  BarChartGroupData(x: 0, barRods: [BarChartRodData(y: 10)]),
                  BarChartGroupData(x: 1, barRods: [BarChartRodData(y: 20)]),
                  BarChartGroupData(x: 2, barRods: [BarChartRodData(y: 15)]),
                ],
                gridData: FlGridData(
                  show: true,
                  drawHorizontalLine: true,
                  drawVerticalLine: true,
                )
              )
            ),
          ),
        ),
      ),
    );
  }
}