安卓OverlayItem未显示消息

Question

这是我的代码：

OverlayItem overlayItem = new OverlayItem(point, "Test", "Hello");
itemizedOverlay.addOverlay(overlayItem);
mapOverlays.add(itemizedOverlay);

当我运行这个应用程序时，我可以看到地图上有我的项目，但当点击它时，什么也不会发生。我期望看到一个带有"Test ... Hello“的信箱。我想我忘了什么。谢谢你的帮助。

Answer 1

覆盖onTap(int索引)，如下所示.

   public class CustomItemizedOverlay extends ItemizedOverlay<OverlayItem> {

   private ArrayList<OverlayItem> mapOverlays = new ArrayList<OverlayItem>();

   private Context context;

   public CustomItemizedOverlay(Drawable defaultMarker) {
        super(boundCenterBottom(defaultMarker));
   }

   public CustomItemizedOverlay(Drawable defaultMarker, Context context) {
        this(defaultMarker);
        this.context = context;
   }

   @Override
   protected OverlayItem createItem(int i) {
      return mapOverlays.get(i);
   }

   @Override
   public int size() {
      return mapOverlays.size();
   }

   @Override
   protected boolean onTap(int index) {
      OverlayItem item = mapOverlays.get(index);
      AlertDialog.Builder dialog = new AlertDialog.Builder(context);
      dialog.setTitle(item.getTitle());
      dialog.setMessage(item.getSnippet());
      dialog.show();
      return true;
   }

   public void addOverlay(OverlayItem overlay) {
      mapOverlays.add(overlay);
       this.populate();
   }

}