如何在主飞镖中运行图表？ -扑

Question

我试图从一个库中快速地运行图表。我无法使用main.dart。

Main.dart：

import './widgets/chart.dart';

void main() {
  runApp(
    new MaterialApp(
      home: PointsLineChart(),
    ),
  );
}

chart.dart：

import 'package:flutter/material.dart';
import 'package:charts_flutter/flutter.dart' as charts;

class PointsLineChart extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

  PointsLineChart(this.seriesList, {this.animate});

  /// Creates a [LineChart] with sample data and no transition.
  factory PointsLineChart.withSampleData() {
    return new PointsLineChart(
      _createSampleData(),
      // Disable animations for image tests.
      animate: false,
    );
  }

  @override
  Widget build(BuildContext context) {
    return new charts.LineChart(seriesList,
        animate: animate,
        defaultRenderer: new charts.LineRendererConfig(includePoints: true));
  }

  /// Create one series with sample hard coded data.
  static List<charts.Series<LinearSales, int>> _createSampleData() {
    final data = [
      new LinearSales(0, 5),
      new LinearSales(1, 25),
      new LinearSales(2, 100),
      new LinearSales(3, 75),
    ];

    return [
      new charts.Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
        domainFn: (LinearSales sales, _) => sales.year,
        measureFn: (LinearSales sales, _) => sales.sales,
        data: data,
      )
    ];
  }
}

/// Sample linear data type.
class LinearSales {
  final int year;
  final int sales;

  LinearSales(this.year, this.sales);
}

我得到的错误是在main.dart中，我需要输入一些内容才能运行chart.dart。在PointsLineChart（）中，

它给我错误：

预计需要1个自变量，但找到0个。dart（not_enough_required_arguments） （新）PointsLineChart（列表> seriesList，{布尔动画）}→PointsLineChart

Answer 1

PointsLineChart的构造函数带有两个参数：

PointsLineChart(this.seriesList, {this.animate});

在main.dart中，您不提供任何参数：

home: PointsLineChart(),// here you need to add two arguements!!!

更改代码如下：

runApp(
new MaterialApp(
  home: PointsLineChart(PointsLineChart.createSampleData(), animate: false),
),

）;

还将_createSampleData更改为createSampleData以使其公开。