permission_handler_1

main.dart

import 'package:location/location.dart';
import 'package:permission_handler/permission_handler.dart' as per_handler;

void main() {
  runApp(
    ExchangeShop(),
  );
}

class MapCebu extends StatefulWidget {
  @override
  State<MapCebu> createState() => MapCebuState();
}

class MapCebuState extends State<MapCebu> {
  LocationData currentLocation;
  Location _locationService = Location();

  @override
  void initState() {
    super.initState();
    initPlatformState();
  }

  void initPlatformState() async {
    LocationData myLocation;
    try {
      myLocation = await _locationService.getLocation();
    } catch (e) {
      if (e.code == 'PERMISSION_DENIED')
        error = 'Permission denited';
      else if (e.code == 'PERMISSION_DENITED_NEVER_ASK')
        error =
            'Permission denited - please ask the user to enable it from the app settings';
      bool isShown =
          await per_handler.Permission.contacts.shouldShowRequestRationale;
      if (isShown == false) {
        per_handler.openAppSettings();
        sleep(new Duration(seconds: 2));
      }
      // 位置情報の権限がない場合は、アプリを使えない仕様にする
      exit(0);
    }

    setState(() {
      currentLocation = myLocation;
    });
  }
}