如何在折线图 x 轴抖动中传递字符串参数

Question

我试图在颤振应用程序中制作折线图，Y 轴作为值（整数）和 X 轴作为日期（字符串），如下图所示，但颤振预定义类不允许我这样做，因为当我尝试将字符串作为参数发送然后它抛出错误说String is not Subtype of int，我是颤振的新手，请帮助我..

我试图做的例子点击这里。

这就是我想显示我的图表的方式。

Answer 1

_graphSection(ScreenType type) {
final customTickFormatter =
charts.BasicNumericTickFormatterSpec((num value) {
  if (value == 0) {
    return "Mon";
  } else if (value == 1) {
    return "Tue";
  } else if (value == 2) {
    return "Wed";
  } else if (value == 3) {
    return "Thr";
  } else if (value == 4) {
    return "Fri";
  } else if (value == 5) {
    return "Sat";
  } else if (value == 6) {
    return "Sun";
  }
});

return SizedBox(
  height: 200,
  child: charts.LineChart(
    _createSampleData(),
    defaultRenderer:
    charts.LineRendererConfig(includeArea: true, stacked: true),
    animate: true,
    // Sets up a currency formatter for the measure axis.

    primaryMeasureAxis: new charts.NumericAxisSpec(
      tickProviderSpec:
      new charts.BasicNumericTickProviderSpec(desiredTickCount: 6),
    ),
    domainAxis: charts.NumericAxisSpec(
      tickProviderSpec:
      charts.BasicNumericTickProviderSpec(desiredTickCount: 7),
      tickFormatterSpec: customTickFormatter,
    ),
  ),
);
}

_createSampleData() {
final myFakeDesktopData = [
  new LinearSales(0, 1000),
  new LinearSales(1, 2000),
  new LinearSales(2, 4000),
  new LinearSales(3, 1000),
  new LinearSales(4, 4000),
  new LinearSales(5, 5000),
  new LinearSales(6, 6000),
];

var shadowColor = chartColor.Color(r: 240, g: 246, b: 244, a: 160);
var yellowThemeColor = chartColor.Color.fromHex(code: "#f4e400");

return [
  charts.Series<LinearSales, int>(
    id: 'Cost',
    domainFn: (LinearSales row, _) => row.day,
    measureFn: (LinearSales row, _) => row.sales,
    colorFn: (_, __) => yellowThemeColor,
    areaColorFn: (_, __) => shadowColor,
    data: myFakeDesktopData,
  )
];
}

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