pointers property

Add a list of gauge pointer to the radial gauge and customize each pointer by adding it to the pointers collection.

Also refer GaugePointer

Widget build(BuildContext context) {
   return Container(
       child: SfRadialGauge(
         axes:<RadialAxis>[RadialAxis(
            pointers: <GaugePointer>[MarkerPointer(value: 50)],
           )]
       ));
}