在Android中具有固定点数的Google Maps用户可编辑多边形? [英] Google Maps user-editable polygon with fixed number of points in Android?

问题描述

我正在使用Google Map多边形标记，我已经预定义了纬度/经度数组，并且需要设置多边形区域，这对我来说很好，但是当我拖动标记多边形线不变时，它应该具有拖动标记时会发生变化.

I am working on Google Map polygon marker, I have predefined lat/long array, and need to set polygon area, It is working fine for me, but when I drag the marker polygon line doesn't change, it should have to be change as I drag the marker.

这是我的问题，我将放一张图片来说明它.

Here is my problem, I'll put a picture to illustrate it easier.

这是代码:

    myMap.setOnMarkerDragListener(new GoogleMap.OnMarkerDragListener() {
        @Override
        public void onMarkerDragStart(Marker marker) {
        }

        @Override
        public void onMarkerDrag(Marker marker) {
            updateMarkerLocation(marker);
            drawPolygon(coordinates);

        }

        private void updateMarkerLocation(Marker marker) {

            LatLng latLng = (LatLng) marker.getTag();
            int position = coordinates.indexOf(latLng);
            if (position >= 0) {
                coordinates.set(position, marker.getPosition());
                marker.setTag(marker.getPosition());
            }
        }

        @Override
        public void onMarkerDragEnd(Marker marker) {

        }
    });
}

private void drawPolygon(List<LatLng> coordinates) {

    if (polygon != null) {
        polygon.remove();
    }

    PolygonOptions polygonOptions = new PolygonOptions();
    polygonOptions.fillColor(Color.GREEN);
    polygonOptions.strokeColor(Color.GREEN);
    polygonOptions.strokeWidth(3);
    polygonOptions.addAll(coordinates);
    polygon = myMap.addPolygon(polygonOptions);

}

像上面的图像一样，我的标记移动了，但没有形成多边形.

like above image my marker move but not make polygon.

坐标包含来自sqlite的多边形坐标

推荐答案

似乎您正在使用Marker标记存储多边形点的最后显示的坐标(LatLng).要显示的坐标存储在coordinates是吗?

It looks like you're using the Marker tag to store the last displayed coordinate (LatLng) of the polygon point. The coordinates to be displayed are stored in coordinates yes?

如果是这样，那么我猜你的代码应该是:

If so then I'm guessing your code should be:

private void updateMarkerLocation(Marker marker) {
  LatLng latLng = (LatLng) marker.getTag();
  int position = coordinates.indexOf(latLng);
  if (position >= 0) {
    coordinates.set(position, marker.getPosition());
    marker.setTag(marker.getPosition());
  }
}

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