replace rootbundle

lib/view/3d_view/measure_3d_view.dart

@@ -46,7 +46,7 @@ class _Measure3DViewState extends State<Measure3DView> {
 
   Future<String> _loadHTMLFromAssets(String path) async {
     try {
-      return await rootBundle.loadString(path);
+      return await DefaultAssetBundle.of(context).loadString(path);
     } catch (e) {
       return Future.error(e);
     }