charts_flutter - 如何设置 x 轴刻度上的间隔

Question

我正在使用以下代码段绘制一些实时时间序列折线图：

  new SizedBox(
    height: MediaQuery.of(context).size.height / 4,
    child: new charts.TimeSeriesChart([
      new charts.Series<HistoryData, DateTime>(
          id: 'test',
          colorFn: (_, __) => colourArray[dataArrayName],
          data: dataArray,
          domainFn: (HistoryData sales, _) => sales.date,
          measureFn: (HistoryData sales, _) => sales.historyValue)
    ],
        animate: true,
        dateTimeFactory: const charts.LocalDateTimeFactory()),
  )

class HistoryData {
  final DateTime date;
  final double historyValue;

  HistoryData(this.date, this.historyValue);
}

数据显示正常，但我注意到只有一个 x 轴标签：

我想知道是否有人可以帮助我弄清楚如何制作它，以便在 x 轴上有许多均匀分布的刻度。

谢谢

编辑：dataArray是一个类型的变量List<HistoryData>

这是印刷品：

I/flutter (19864): [Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryData', Instance of 'HistoryDat...

其中有 60 个HistoryData对象，List每个对象中的每个date值彼此HistoryData相隔 2 秒。

Answer 1

charts.TimeSeriesChart(
    _createSampleData(),
    animate: true,
    domainAxis: new charts.DateTimeAxisSpec(
      tickProviderSpec: charts.DayTickProviderSpec(increments: [1]),
      tickFormatterSpec: new charts.AutoDateTimeTickFormatterSpec(
        day: new charts.TimeFormatterSpec(
            format: 'EEE', transitionFormat: 'EEE', noonFormat: 'EEE'),
      ),
      showAxisLine: false,
    ),
  ),

此行设置要在域或底轴上显示刻度的数量

tickProviderSpec: charts.DayTickProviderSpec(increments: [1]),

将增量更改为 2 和 3 并检查输出