断言失败：第 4973 行 pos 16：“孩子是！” ParentDataElement<ParentData>'：不正确

Question

在我的 Flutter 应用程序中，当我移动地图时，更改后的位置应该显示在底部的容器中，如下所示 ，它确实显示了，但是当我向上滚动该位置时，它会闪烁 。

这些是弹出的错误消息

我是颤振新手，我迫切需要这方面的帮助，请，谢谢。

遵循我正在处理的屏幕代码

    // @dart=2.9
    import 'package:firebase_auth/firebase_auth.dart';
    import 'package:flutter/material.dart';
    import 'package:google_maps_flutter/google_maps_flutter.dart';
    import 'package:groceryapp/providers/auth_provider.dart';
    import 'package:groceryapp/providers/location_provider.dart';
    import 'package:groceryapp/screens/homeScreen.dart';
    import 'package:groceryapp/screens/landing_screen.dart';
    import 'package:groceryapp/screens/login_screen.dart';
    import 'package:groceryapp/screens/main_screen.dart';
    import 'package:provider/provider.dart';
    import 'package:flutter_spinkit/flutter_spinkit.dart';
    
    class MapScreen extends StatefulWidget {
      static const String id= 'map-screen';
      //const MapScreen({Key? key}) : super(key: key);
    
      @override
      _MapScreenState createState() => _MapScreenState();
    }
    
    class _MapScreenState extends State<MapScreen> {
    
      LatLng currentLocation = LatLng(37.421632, 122.084664);
      GoogleMapController _mapController;
      bool _locating = false;
      bool _loggedIn=false;
      User user;
    
      @override
      void initState() {
        getCurrentUser();
        super.initState();
      }
      void getCurrentUser() {
        User user = FirebaseAuth.instance.currentUser;
        if(user!=null){
          setState((){
            _loggedIn=true;
            user= FirebaseAuth.instance.currentUser;
          });
        }
        else{
    
        }
      }
      @override
      Widget build(BuildContext context) {
        final locationData = Provider.of<LocationProvider>(context);
        final _auth = Provider.of<AuthProvider>(context);
    
        setState((){
          currentLocation = LatLng(
              locationData.latitude,
              locationData.longitude
          );
        });
        void onCreated(GoogleMapController controller){
          _mapController = controller;
        }
        return Scaffold(
          body: SafeArea(
            child:Column(
              children:[
                Expanded(
                  child: Stack(
                    children : [
                      GoogleMap(
                      initialCameraPosition: CameraPosition(
                        target: currentLocation,
                        zoom:14.4746,
                      ),
                      zoomControlsEnabled: false,
                      minMaxZoomPreference: MinMaxZoomPreference(1.5,20.8),
                      myLocationEnabled: true,
                      myLocationButtonEnabled: true,
                      mapType: MapType.normal,
                      mapToolbarEnabled: true,
                      onCameraMove: (CameraPosition position)
                      {
                        setState((){
                          _locating=true;
                        });
                        locationData.onCameraMove(position);
                      },
                      onMapCreated: onCreated,
                      onCameraIdle: (){
                        setState((){
                          _locating=false;
                        });
                        locationData.getMoveCamera();
                      },
                    ),
                      Center(
                        child: Container(
                          height:50,
                          margin:EdgeInsets.only(bottom:40),
                          child: Image.asset(
                              'images/marker.png',
                              color: Colors.indigoAccent
                          ),
                        ),
                      ),
                      Center(
                        child: SpinKitPulse(
                          color:Colors.indigoAccent,
                          size:100.0,
                        ) ,
                      ),
                     ],
                  ),
                ),
                Container(
                  height:230,
                  width:MediaQuery.of(context).size.width,
                  color: Colors.white,
                  child:Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children:[
                      _locating ? LinearProgressIndicator(
                        backgroundColor: Colors.transparent,
                        valueColor: AlwaysStoppedAnimation<Color>(Theme.of(context).primaryColor),
                      ) : Container(),
                      Padding(
                        padding: const EdgeInsets.only(
                            left: 10,
                            right: 20
                        ),
                        child: TextButton.icon(
                          onPressed:(){},
                          icon: Icon(
                            Icons.location_searching,
                            color: Theme.of(context).primaryColor,
                          ),
                          label: Flexible(
                            child: Text(
                             _locating ? 'Locating..'
                                 : locationData.selectedAddress == null?
                             'Locating..':
                             locationData.selectedAddress.featureName,
                              overflow:TextOverflow.ellipsis,
                              style: TextStyle(
                                  fontWeight:FontWeight.bold,
                                fontSize: 20,
                                color: Colors.black,
                              ),
                            ),
                          ),
                        ),
                      ),
                      Padding(
                        padding: const EdgeInsets.only(
                            left: 20,
                            right: 20
                        ),
                        child: Text(
                          _locating ? '': locationData.selectedAddress == null?'':
                          locationData.selectedAddress.addressLine,
                          style: TextStyle(
                              color:Colors.black54,
                          ),
                        ),
                      ),
                      SizedBox(height:30,),
                      Padding(
                        padding: const EdgeInsets.all(15.0),
                        child: SizedBox(
                          width: MediaQuery.of(context).size.width-40,
                          child: AbsorbPointer(
                            absorbing: _locating ? true : false,
                            child: TextButton(
                              style:TextButton.styleFrom(
                                backgroundColor:_locating ?
                                Colors.grey: Theme.of(context).primaryColor,
                              ),
                              onPressed:(){
                                locationData.savePrefs();
    
                                if(_loggedIn==false){
                                  Navigator.pushNamed(context, LoginScreen.id);
                                }
                                else{
                                  setState((){
                                    _auth.latitude= locationData.latitude;
                                    _auth.longitude= locationData.longitude;
                                    _auth.address=locationData.selectedAddress.addressLine;
                                    _auth.location=locationData.selectedAddress.featureName;
                                  });
                                  _auth.updateUser(
                                    id: user?.uid,
                                    number: user?.phoneNumber,
                                  );
                                  Navigator.pushNamed(context, MainScreen.id);
                                }
                              },
                              child: Text(
                                'CONFIRM LOCATION',
                                style: TextStyle(
                                    color: Colors.white,
                                ),
                              ),
                            ),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),
        );
      }
    }

Answer 1

在第 1 行用 Expanded 包裹容器。 113.

信息：https://api.flutter.dev/flutter/widgets/Expanded-class.html

Answer 2

删除灵活的小部件

Flexible(
                        child: Text(
                         _locating ? 'Locating..'
                             : locationData.selectedAddress == null?
                         'Locating..':
                         locationData.selectedAddress.featureName,
                          overflow:TextOverflow.ellipsis,
                          style: TextStyle(
                              fontWeight:FontWeight.bold,
                            fontSize: 20,
                            color: Colors.black,
                          ),