像这样在xml中扩展我的Mapview我已经按如下方式实现了自定义mapView:-publicclassCustomMapViewextendsMapView{privateViewParentmViewParent;publicCustomMapView(Contextcontext){super(context);}publicCustomMapView(Contextcontext,AttributeSetattrs){super(context,attrs);}publicCustomMapView(Contextcontext,AttributeSetattrs,intde