Flutter 图表 PanAndZoomBehavior 不会缩放手势的中心

Question

I used https://github.com/google/charts inside my flutter app. It works great. But when i zoom on chart, the zoom happens but in the wrong place! It starts expanding keeping the left static. The effect is the chart slide under your finger zooming not in the point you are zooming to. Is there a way to zoom like you zoom on a picture on gallery?

code of my chart

Widget build(BuildContext context) {
    return new charts.LineChart(
      _chartSeriesFromChartData(seriesList),
      animate: false,
      defaultRenderer: charts.LineRendererConfig(includeArea: true, includePoints: true),
      primaryMeasureAxis: charts.NumericAxisSpec(tickProviderSpec: charts.BasicNumericTickProviderSpec(desiredTickCount: 8)),
      behaviors: [ZoomBehaviour()],
    )

Answer 1

你可以在你的代码中使用这样的代码：

behaviors: [new charts.PanAndZoomBehavior()],

或者，如果您想在我们的图表中按项目进行选择，您可以使用：

behaviors: [new charts.SeriesLegend()],

如果你想使用其中的两个，也许你可以使用：

behaviors: [new charts.SeriesLegend(), new charts.PanAndZoomBehavior()],

祝你好运快乐编码