失败的断言：第 35 行 pos 18：'longitude != null'：不是真的

问题描述

我仍在尝试使用我的出租车应用程序。我应该在何处搜索下车地点，但每次用户搜索一个地点并使用 Google 自动完成点击它时，它不断出现此错误：

[ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: 'package:google_maps_flutter_platform_interface/src/types/location.dart': Failed assertion: line 35 pos 18: 'longitude != null': is not true.

我曾尝试使用 FutureBuilder 小部件，因为该应用程序依赖于等待另一个无效的操作完成。应用程序仍然崩溃，因此其他方法没有执行。这是错误指向的方法：


  Future<void> getPlaceDirection() async
  {
    var initialPos = Provider.of<AppData>(context,listen: false).pickUpLocation;
    var finalPos = Provider.of<AppData>(context,listen: false).dropOffLocation;

    var pickUpLatLng = LatLng(initialPos.latitude,initialPos.longitude);
    var dropOffLatLng = LatLng(finalPos.latitude,finalPos.longitude);

    showDialog(
      context: context,builder: (BuildContext content) => ProgressDialog(message: "Please wait...",)
    );
    var details = await AssistantMethods.obtainPlaceDirectionDetails(pickUpLatLng,dropOffLatLng);

    setState(() {
          tripDirectionDetails = details;
        });
    Navigator.pop(context);

    print("This is encoded points :");
    print(details.encodedPoints);

    PolylinePoints polylinePoints = PolylinePoints();
    List<PointLatLng> decodedPolyLinePointsResult = polylinePoints.decodePolyline(details.encodedPoints);
     
    pLineCoordinates.clear();

    if (decodedPolyLinePointsResult.isNotEmpty)
    {
      decodedPolyLinePointsResult.forEach((PointLatLng pointLatLng)
      {
         pLineCoordinates.add(LatLng(pointLatLng.latitude,pointLatLng.longitude));
      });
    }

    polylineSet.clear();

    setState(() {
     Polyline polyline = Polyline(
      color: orange,polylineId: PolylineId("PolylineID"),jointType: JointType.round,points: pLineCoordinates,width: 5,startCap: Cap.roundCap,endCap: Cap.roundCap,geodesic: true,);

      polylineSet.add(polyline);
        });

      LatLngBounds latLngBounds;
      if(pickUpLatLng.latitude > dropOffLatLng.latitude && pickUpLatLng.longitude > dropOffLatLng.longitude)
      {
        latLngBounds = LatLngBounds(southwest: dropOffLatLng,northeast: pickUpLatLng);
      }
      else if(pickUpLatLng.longitude> dropOffLatLng.longitude)
      {
        latLngBounds = LatLngBounds(southwest: LatLng(pickUpLatLng.latitude,dropOffLatLng.longitude),northeast: LatLng(dropOffLatLng.latitude,pickUpLatLng.longitude));
      }
      else if(pickUpLatLng.latitude > dropOffLatLng.latitude)
      {
        latLngBounds = LatLngBounds(southwest: LatLng(dropOffLatLng.latitude,pickUpLatLng.longitude),northeast: LatLng(pickUpLatLng.latitude,dropOffLatLng.longitude));
      } 
      else 
      {
        latLngBounds = LatLngBounds(southwest: pickUpLatLng,northeast: dropOffLatLng);
      }

      newGoogleMapController.animateCamera(CameraUpdate.newLatLngBounds(latLngBounds,70));

      Marker pickUpLocMarker = Marker(
        icon: BitmapDescriptor.defaultMarkerWithHue(BitmapDescriptor.hueBlue),infoWindow: InfoWindow(title: initialPos.placeName,snippet: "My location"),position:  pickUpLatLng,markerId: MarkerId("pickUpId"),);

      Marker dropOffLocMarker = Marker(
        icon: BitmapDescriptor.defaultMarkerWithHue(BitmapDescriptor.hueRed),infoWindow: InfoWindow(title: finalPos.placeName,snippet: "Drop-off location"),position:  dropOffLatLng,markerId: MarkerId("dropOffId"),);

      setState(() {
              markerSet.add(pickUpLocMarker);
              markerSet.add(dropOffLocMarker);
            });

      Circle pickUpLocCircle = Circle(
        fillColor: Colors.blue,center: pickUpLatLng,radius: 12,strokeWidth: 4,strokeColor: Colors.blueAccent,circleId: CircleId("pickUpId")
      );

      Circle dropOffLocCircle = Circle(
        fillColor: Colors.red,center: dropOffLatLng,strokeColor: Colors.redAccent,circleId: CircleId("dropOffId"),); 

      setState(() {
              circleSet.add(pickUpLocCircle);
              circleSet.add(dropOffLocCircle);
            }); 
  }

解决方法

暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！

如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。

小编邮箱:dio#foxmail.com (将#修改为@）

google-geolocation googleplacesautocomplete