Google Map陷入困境

Question

当我将Google Map集成到Flutter中时，第一次启动包含Google Map小部件的屏幕时，它会冻结我的应用程序。     请注意，我使用的是标签视图小部件，而Google地图是我应用中的第三个标签。

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'dart:async';

class MapModlue extends StatefulWidget {
  @override
  State createState() => MapModlueState();
}

class MapModlueState extends State<MapModlue> {
  GoogleMapController mapController;
  double opacity = 0.0;

  @override
  Widget build(BuildContext context) {
    return Container(
        padding: new EdgeInsets.all(0.0),
        decoration:
            new BoxDecoration(color: Color.fromRGBO(240, 240, 240, 1.0)),
        child: Opacity(
            opacity: opacity,
            child: GoogleMap(
              onMapCreated: _onMapCreated,
            )));
  }

  // ignore: invalid_override

  void _onMapCreated(GoogleMapController controller) {
    Timer _timer = new Timer(const Duration(milliseconds: 400), () {
      // this timer to hide black screen that appear before map loading
      setState(() {
        mapController = controller;
        opacity = 1.0;
      });`enter code here`
    });
  }
}