Android 如何添加/删除ArcGISTiledMapServiceLayer

我有一张osmdroid地图。我打算在上面加一层，它不是覆盖层，而是一层。当我添加图层时没有问题，但是当我尝试删除图层时。有一个例外：

该图层不是当前地图的子图层

添加和删除图层的代码为：

iLayer\u列表\u适配器。切换\u状态==true {

                    Log.i("ADDING LAYER... :", "Adding...");
                    mapView.addLayer(dmsl);
                    Log.i("Layers ::", ""+mapView.getLayers());
                    layer_added_falg=true;

            }

            else if(Layer_List_Adapter.toggle_status==false)
            {

                Log.i("A", "A");

                    if(layer_added_falg==true)
                    {
                    try
                    {
                        Log.i("REMOVING LAYER... :", "Removing...");
                        Log.i("Layers ::", ""+mapView.getLayers());
                        mapView.removeLayer(mapView.getLayerByID(layerId));
                        mapView.refreshDrawableState();
                        layer_added_falg=false;
                    }
                    catch (Exception e) {
                        // TODO: handle exception

                        Log.e("ERROR :", e.getMessage());
                    }
                    }

                    else
                    {

                    }

            }