BitmapDescriptorFactory.fromBitmap（bitmap_Image）在Google Map v2上设置自定义标记时出错

Question

LinearLayout v = (LinearLayout)view.findViewById(R.id.test2);
v.setDrawingCacheEnabled(true);
v.buildDrawingCache();
final Bitmap bm = view.getDrawingCache();
BitmapDescriptor iconBitmap = BitmapDescriptorFactory.fromBitmap(bm);


MarkerOptions markerOptions = new MarkerOptions().position(new LatLng(latitude[i], longitude[i])).title(name[i]).
                            alpha((float) 0.8).
                            title("3.5").
                            icon(iconBitmap);
googleMap.addMarker(markerOptions);

抛出以下错误

  

显示java.lang.NullPointerException   com.google.android.gms.maps.internal.IGoogleMapDelegate $ ZZA $ zza.addMarker（未知   源）