集群标记后，osmdroid标记信息窗口不显示

Question

I'm using osmdroid to display open street map in an android app the problem is when clustering markers when click on marker, info window of markers do not shows. this is how i add markers for clustering:

    RadiusMarkerClusterer poiMarkers = new RadiusMarkerClusterer(this);
    Drawable clusterIconD = getResources().getDrawable(R.drawable.marker_cluster);
    Bitmap clusterIcon = ((BitmapDrawable) clusterIconD).getBitmap();
    poiMarkers.setIcon(clusterIcon);
    poiMarkers.getTextPaint().setColor(Color.WHITE);
    poiMarkers.getTextPaint().setTextSize(12 * getResources().getDisplayMetrics().density); //taking into account the screen density
    poiMarkers.mAnchorU = Marker.ANCHOR_CENTER;
    poiMarkers.mAnchorV = Marker.ANCHOR_CENTER;
    poiMarkers.mTextAnchorV = 0.40f;
    map.getOverlays().add(poiMarkers);

    for (int i = 0; i < places.size(); i++) {
        final Marker startMarker = new Marker(map);
        startMarker.setPosition(new GeoPoint(places.get(i).getLat(), places.get(i).getLng()));

        startMarker.setIcon(getResources().getDrawable(R.drawable.ic_new_loc));

        startMarker.setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_CENTER);
        MyInfoWindow infoWindow = new MyInfoWindow(R.layout.map_marker_info_window, map);
        infoWindow.setPlace(places.get(i));
        startMarker.setInfoWindow(infoWindow);
        poiMarkers.add(startMarker);
    }

Answer 1

ReadiusMarkerClusterer is not supposed to show info windows for clusters. A cluster represents a group of individual markers and so it's impossible to decide, which info window should be displayed.

You can check source code of the RadiusMarkerClusterer class.

Markers (which represents clusters) are instantiated in the method buildClusterMarker :

@Override public Marker buildClusterMarker(StaticCluster cluster, MapView mapView) {
    Marker m = new Marker(mapView);
    m.setPosition(cluster.getPosition());
    m.setInfoWindow(null); //<===== there you can see, no info window
    m.setAnchor(mAnchorU, mAnchorV);

    Bitmap finalIcon = Bitmap.createBitmap(mClusterIcon.getWidth(), mClusterIcon.getHeight(), mClusterIcon.getConfig());
    Canvas iconCanvas = new Canvas(finalIcon);
    iconCanvas.drawBitmap(mClusterIcon, 0, 0, null);
    String text = "" + cluster.getSize();
    int textHeight = (int) (mTextPaint.descent() + mTextPaint.ascent());
    iconCanvas.drawText(text,
            mTextAnchorU * finalIcon.getWidth(),
            mTextAnchorV * finalIcon.getHeight() - textHeight / 2,
            mTextPaint);
    m.setIcon(new BitmapDrawable(mapView.getContext().getResources(), finalIcon));

    return m;
}

If you want to have info windows for your clusters, you can create custom MarkerClusterer class, by inheriting from RadiusMarkerClusterer and overriding this method. Just call parent version and inject your desired info window into the Marker instance.