labelPosition property
Position of the data label.
Note: This is applicable for pie and doughnut series types alone.
Defaults to ChartDataLabelPosition.inside.
Widget build(BuildContext context) {
  return SfCircularChart(
    series: <PieSeries<SalesData, num>>[
      PieSeries<SalesData, num>(
        dataLabelSettings: DataLabelSettings(
          isVisible: true,
          labelPosition: ChartDataLabelPosition.outside
        ),
      ),
    ],
  );
}
Implementation
final ChartDataLabelPosition labelPosition;