问OpenLayers如何停止OpenLayers 6中指针的传播

EN

  import { MapBrowserPointerEvent as olMapBrowserPointerEvent } from 'ol/events/Event';

  const simpleLineInteraction: PointerInteraction = new PointerInteraction({
  handleDownEvent: handleDownEventHandler,
  handleDragEvent: handleDragEventHandler,
  handleUpEvent: handleUpEventHandler,
  stopDown: stopDownHandler
  });
  function stopDownHandler(evt: olMapBrowserPointerEvent) {
  return false;
  }

import  MapBrowserEvent  from 'ol/MapBrowserEvent';
const simpleLineInteraction: PointerInteraction = new PointerInteraction({
handleDownEvent: handleDownEventHandler,
handleDragEvent: handleDragEventHandler,      
handleUpEvent: handleUpEventHandler,
stopDown: stopDownHandler
});
function stopDownHandler(evt: MapBrowserEvent<MouseEvent>) {
return false;
}

function handleDownEventHandler(evt: MapBrowserEvent<MouseEvent>) {
if (evt.originalEvent.buttons !== 2) {
downClick = evt.coordinate;
return true;
} else { return false; }
}