onCreatePointerRenderer property

MarkerPointerRendererFactory<MarkerPointerRenderer>? onCreatePointerRenderer

The callback that is called when the custom renderer for the marker pointer is created. and it is not applicable for built-in marker pointer

The marker pointer is passed as the argument to the callback in order to access the pointer property

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

Called before creating the renderer
MarkerPointerRenderer handleCreatePointerRenderer(MarkerPointer pointer){
final _CustomPointerRenderer _customPointerRenderer =
                                                _CustomPointerRenderer();
return _customPointerRenderer;
}

class _CustomPointerRenderer extends MarkerPointerRenderer{
_CustomPointerRenderer class implementation
}

Implementation

final MarkerPointerRendererFactory<MarkerPointerRenderer>?
    onCreatePointerRenderer;