问题是google_maps_flutter软件包需要访问您位置的权限，但该软件包没有本机代码来请求该权限。

因此，您需要编写本机代码或仅安装另一个能够获得该许可权的软件包。

安装此程序：https :
//pub.dartlang.org/packages/location

然后：

getLocationPermission() async {
    final Location location = new Location();
    try {
      location.requestPermission(); //to lunch location permission popup
    } on PlatformException catch (e) {
      if (e.code == 'PERMISSION_DENIED') {
        print('Permission denied');
      }
    }
  }

或者，如果您想要更坚实的代码，这是我用于某些项目的代码（带有位置包）：

//Show some loading indicator depends on this boolean variable
bool askingPermission = false;

@override
  void initState() {
    this.getLocationPermission();
    super.initState();
  }

  Future<bool> getLocationPermission() async {
    setState(() {
      this.askingPermission = true;
    });
    bool result;
    final Location location = Location();
    try {
      if (await location.hasPermission())
        result = true;
      else {
        result = await location.requestPermission();
      }
      print('getLocationPermission: '
          '${result ? 'Access Allowed' : 'Access Denied'}');
    } catch (log, trace) {
      result = false;
      print('getLocationPermission/log: $log');
      print('getLocationPermission/trace: $trace');
    } finally {
      setState(() {
        this.askingPermission = false;
      });
    }
    return result;
  }