animationDuration property
Determines the animation time of trendline.
Defaults to 1500 .
Widget build(BuildContext context) {
  return SfCartesianChart(
    series: <CartesianSeries<ChartData,String>>[
      LineSeries<ChartData,String>(
        trendlines: <Trendline>[
          Trendline(animationDuration: 150)
        ]
      )
    ]
  );
}
Implementation
final double animationDuration;