诺基亚在这里地图:让用户在地图上绘制多边形

Question

我想为用户创建一个选项，以在地图上绘制多边形，

应该绘制点击地图上的绘图，当再次单击第一个点时，应绘制半透明多边形。

我该如何实现？

Answer 1

您可以将单击侦听器添加到地图中创建标记的地图。您创建的第一个标记应该具有单击侦听器来结束编辑器（删除您首先添加到地图上的侦听器）每次在地图中创建新标记时，都可以绘制多边形。

//Supposing map is an instance of our map.
//Suposing we have a global instance of a container called myContainer and has been already added to the map
//suposing we have a global variable called polygon and has been already added to the map
map.addListener("click", addMarker);
function addMarker(evt){
  var pixelGeo =  map.pixelToGeo(evt.displayX, evt.displayY);
  var coordinate = new nokia.maps.geo.Coordinate(pixelGeo.latitude, pixelGeo.longitude);
  var marker = new nokia.maps.map.StandardMarker(coordinate);
  //compare if it's the first created marker, so we can add an event listener for ending
  if(myContainer.objects.getLength() > 0){
      //add event listener to marker
      marker.addListener("click",finishPolygon);
  }
  //add marker to container
  myContainer.objects.add(marker);
  //paint polygon acording to markers
  paintPoly();
}
function paintPoly(){
   //grab coordinates from markers and draw polyline
   var aMarkers = myContainer.objects.asArray();
   var aCoords = [];
   for(var marker in aMarkers){
       var marker = aMarkers[marker];
       aCoords.push(marker.coordinate);
   }
   //remove polygon instance from map
   map.objects.remove(polygon);
   //add new polygon
   polygon = new nokia.maps.map.Polygon(
        aCoords,
        {
            pen: { strokeColor: #000, lineWidth: 1 },
            brush: { color: #ababab }
        }
   );
}

希望这可以帮助您作为指导。您可以在此处查看MAPS开发人员页面中的对象属性和功能