overlayRadius property Null safety

double? overlayRadius

Radius of the overlay drawn around the marker pointer.

If enableDragging is set to true, while touching the marker pointer in mobile and on hovering/clicking the marker pointer in web, the overlay will be displayed. If enableDragging is set to false, the overlay will not be displayed.

If the value of this property is null, the overlay radius is calculated by adding 15 logical pixels to the marker's width. Else it will be rendered with the specified value as radius.

If it has to be hidden, 0 can be set to this property.

Defaults to null.

Widget build(BuildContext context) {
   return Container(
       child: SfRadialGauge(
            pointers: <GaugePointer>[MarkerPointer(value: 50,
                enableDragging: true,
               overlayColor: Colors.red[50],
                overlayRadius: 35)],


final double? overlayRadius;