ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: Null check operator used on a null-CodePudding

Hi Everyone i am facing an issue (null check operator used on null value) when i remove this operator it gives me Error here is my code

Future<void> getDirectionDetails() async {
    var pickUpDetails =
        Provider.of<AppData>(context, listen: false).currentPickupAddress;
    var destinationDetails =
        Provider.of<AppData>(context, listen: false).destinationAddress;

    var pickUpLatLang =
        LatLng(pickUpDetails!.latitude!, pickUpDetails.longitude!);
    var destinationLatLang =
        LatLng(destinationDetails!.latitude!, destinationDetails.longitude!);

    showDialog(
        context: context,
        builder: (BuildContext context) =>
            ProgressDialog(status: "Please Wait"));

    var locationDetails = await GeocodeHelper.getDirectionDetails(
        pickUpLatLang, destinationLatLang);
    print(locationDetails.EncodingPoints);
    Navigator.pop(context);
  }

And this is my Class from where i am getting this information.

class AppData extends ChangeNotifier {
  Address? currentPickupAddress;
  Address? destinationAddress;

  void updatePickupAddress(Address pickup) {
    currentPickupAddress = pickup;
    notifyListeners();
  }

  void updateDestinationAddress(Address destination) {
    destinationAddress = destination;
    notifyListeners();
  }
}

CodePudding user response：

I guess the problem is in this block of code

    var pickUpLatLang =
        LatLng(pickUpDetails!.latitude!, pickUpDetails.longitude!);
    var destinationLatLang =
        LatLng(destinationDetails!.latitude!, destinationDetails.longitude!);

See you are force unwrapping the pickUpDetails,latitude and longitude without checking if there value is null or not which gives the issue.

you can try the following

    var pickUpLatLang =
        LatLng(pickUpDetails?.latitude??0, pickUpDetails?.longitude??0);
    var destinationLatLang =
        LatLng(destinationDetails?.latitude??0, destinationDetails?.longitude??0);

Of course I'm assuming that latitude and longitude are of type int, if not please provide the suitable default value.

CodePudding user response：

I've just recheck my code and found an error from where i was getting my latitude and logitude values. Before

currentData.latitude = response["result"]["geometry"]["location.lat"];
currentData.longitude = response["result"]["geometry"]["location.lng"];

After

currentData.latitude = response["result"]["geometry"]["location"]["lat"];
currentData.longitude = response["result"]["geometry"]["location"]["lng"];