Error when clicking on Chart
My Flutter app has an error when I clicked on the chart:
Line 469 of package:syncfusion_flutter_charts/src/chart/user_interaction/trackball.dart
} else if (trackballBehaviorRenderer._trackballTemplate != null) {
final GlobalKey key =
trackballBehaviorRenderer._trackballTemplate!.key as GlobalKey;
final _TrackballTemplateState? trackballTemplateState =
key.currentState as _TrackballTemplateState;
final double duration =
shouldAlwaysShow || (hideDelay == 0 && chartState._enableDoubleTap)
? 200
: hideDelay;
trackballTemplateState?._trackballTimer =
Timer(Duration(milliseconds: duration.toInt()), () {
trackballTemplateState.hideTrackballTemplate();
});
Error is:
type 'Null' is not a subtype of type '_TrackballTemplateState' in type cast