当我删除谷歌地图的覆盖时,我是否需要清除其所有侦听器(出于内存目的)。例如
var rectangle = new google.maps.Rectangle(options);
rectangle.setMap(map);
google.maps.events.addListener(rectangle,'click', mycallback);
......
//delete
//do I need to remove listener first?
rectangle.setMap(null);
rectangle=null;