居中所有标记和折线谷歌地图插件颤振适合屏幕

Posted

技术标签:

【中文标题】居中所有标记和折线谷歌地图插件颤振适合屏幕【英文标题】:Center all marker and poly line google maps plugin flutter fit to screen 【发布时间】:2019-11-05 00:08:50 【问题描述】:

我想将所有标记放在地图中心,并根据设备大小调整缩放 下面是我所做的代码。 我正在使用 google_maps_flutter: ^0.5.18 开发一个基本的“多个标记” 谷歌地图类型的 Flutter 屏幕

    最初设置为静态在添加标记()函数中,

    我将创建标记的地图并将其转换为设置,然后将其传递给谷歌地图小部件

    import 'dart:async';
        import 'dart:math';
        import 'package:flutter/foundation.dart';
        import 'package:flutter/gestures.dart';
        import 'package:flutter/material.dart';
        import 'package:flutter_app/utils/AppConstants.dart';
        import 'package:flutter_app/utils/AppDimens.dart';
        import 'package:flutter_app/utils/CommonColors.dart';
        import 'package:flutter_app/utils/CommonUtils.dart';
        import 'package:flutter_app/utils/networ_util.dart';
    
        import 'package:google_maps_flutter/google_maps_flutter.dart';
        import 'package:permission_handler/permission_handler.dart';
        import 'package:location/location.dart';
        import 'package:screen/screen.dart';
    
        class BusTrackingMap extends StatefulWidget 
          static String tag = "bus-tracking-page";
    
          @override
          State<StatefulWidget> createState() 
            // TODO: implement createState
            return _BusTrackingMapState();
          
        
    
        class _BusTrackingMapState extends State<BusTrackingMap>
            with TickerProviderStateMixin 
          static String homeMarkerId = "101";
          static String schoolMarkerId = "102";
          static String driverMarkerId = "103";
          static String polyLineId = "104";
          String apiKey = "";
          bool isFirstTimeCall = false, myLocationEnabled = true;
          Timer timer;
    
          /*map varibles*/
          static LatLng schoolLatLong = new LatLng(23.027115, 72.552368);
          static LatLng homeLatLong = new LatLng(23.023705, 72.538546);
          static LatLng driverLatLong = new LatLng(23.024311, 72.548505);
          Set<Marker> markerSet = new Set();
          List<Marker> markerList = new List();
          Map<MarkerId, Marker> markers = <MarkerId, Marker>;
          Marker schoolMarker = new Marker(
              markerId: new MarkerId(schoolMarkerId),
              position: schoolLatLong,
              infoWindow: InfoWindow(title: "Parents Location", snippet: ""),
              icon: BitmapDescriptor.fromAsset("images/ic_school.png"));
          Marker homeMarker = new Marker(
              markerId: new MarkerId(homeMarkerId),
              position: homeLatLong,
              infoWindow: InfoWindow(title: "School Location", snippet: ""),
              icon: BitmapDescriptor.fromAsset("images/ic_hhome.png"));
          Marker driverMarker = new Marker(
              markerId: new MarkerId(driverMarkerId),
              position: driverLatLong,
              infoWindow: InfoWindow(title: "Driver Location", snippet: ""),
              icon: BitmapDescriptor.fromAsset("images/ic_bus.png"));
    
          final Set<Polyline> polylineSet = new Set();
          Polyline polyline;
          List<LatLng> _latLongList = new List();
    
          // LatLng driverLatLong=new LatLng(23.028712, 72.570227);
    
          Completer<GoogleMapController> _controller = Completer();
          GoogleMapController _mapController;
    
          static CameraPosition _initialCamera = CameraPosition(
            target: driverLatLong,
            zoom: 14,
          );
    
          /*location update varible*/
    
          BuildContext mContext;
          CameraPosition _currentCameraPosition;
          StreamSubscription<LocationData> _locationSubscription;
          Location _locationService = new Location();
          bool _permission = false;
          String error;
          LocationData _startLocation;
          LocationData _currentLocation;
    
          /*widget varibles*/
          GoogleMap googleMap;
          Scaffold scaffold;
          BitmapDescriptor icon;
          AnimationController rotationController;
    
          @override
          void initState() 
            // TODO: implement initState
            super.initState();
            rotationController = AnimationController(
                duration: const Duration(milliseconds: 1000), vsync: this);
    
            initPlatformState();
            requestPermission();
            addMarker();
            addMarkerAndPolyLine();
            refreshLocationDelay();
            // apiCallEveryInterval();
           
    
          keepPhoneWake() async 
            double brightness = await Screen.brightness;
            Screen.setBrightness(0.5);
            bool isKeptOn = await Screen.isKeptOn;
            Screen.keepOn(true);
          
    
          apiCallEveryInterval() 
            const oneSecond = const Duration(seconds: 20);
            timer = new Timer.periodic(oneSecond, (Timer t) => fetchDriverLocation());
            BitmapDescriptor.fromAssetImage(
                    ImageConfiguration(size: Size(48, 48)), "images/ic_hhome.png")
                .then((onValue) 
              icon = onValue;
            );
          
    
          refreshLocationDelay() 
            rotationController.forward(from: 0.0);
            var _duration = new Duration(seconds: 1);
            return new Timer(_duration, refreshLocation);
          
    
          void addMarker() 
            markers[schoolMarker.markerId] = schoolMarker;
            markers[homeMarker.markerId] = homeMarker;
            markers[driverMarker.markerId] = driverMarker;
            markerSet = Set<Marker>.of(markers.values);
          
    
          void addMarkerAndPolyLine() 
            String encode =
                "msiCmnLmAG?b@?bCBRb@p@hBdCfCfDnAtA|BvAxF|DlDdCb@T^Z`Ax@XV^r@fAnB|BbE|@dAnZiX`GiFzAsA|AkAfBqAtBeBxCBn@g@b@SVCd@@d@J\Nr@^pAx@j@f@vBpBlCpCtAbB^^d@Z^L^Bd@CJAZvDPIDEl@y@N[t@_CdA_DbAyDt@AP[t@y@jCaCpCwBdAm@`@QfC_@jB[jOsBlEKlKIrA@l@dAx@fB`Ao@LI\En@GN@JA~@YhA_@ZSPOFIjE^nBLrBXbKlBfQfEjAb@`Af@~B`BtIxH~D|EtFjHnBoBjFaFhBiBTYZo@J[";
            getRoutes();
            NetworkUtil networkUtil = new NetworkUtil();
            _latLongList = networkUtil.decodePolyline(encode);
            polyline = new Polyline(
                polylineId: PolylineId(polyLineId),
                points: _latLongList,
                color: CommonColors.primaryColor,
                width: 10,
                visible: true);
            polylineSet.add(polyline);
          
    
          void getRoutes()
            if (!isFirstTimeCall) 
              NetworkUtil networkUtil = new NetworkUtil();
              String url = "origin=" +
                  schoolLatLong.latitude.toString() +
                  "," +
                  schoolLatLong.longitude.toString() +
                  "&destination=" +
                  homeLatLong.latitude.toString() +
                  "," +
                  homeLatLong.longitude.toString() +
                  "&key=" +
                  apiKey;
              networkUtil.get(url).then((latLongList) 
                _latLongList = latLongList;
              );
              isFirstTimeCall = true;
              print("Locaton Updated");
            
    
          
          @override
          Widget build(BuildContext context) 
            buildView();
            return scaffold;
          
    
          void buildView() 
            final toolbar = new Row(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: <Widget>[
                InkWell(
                    onTap: () 
                      Navigator.pop(context);
                    ,
                    child: Container(
                      alignment: Alignment.center,
                      height: 24,
                      width: 24,
                      margin: EdgeInsets.only(left: 0, right: 0),
                      padding: EdgeInsets.all(0),
                      child: Icon(
                        Icons.arrow_back_ios,
                        color: CommonColors.primaryColor,
                      ),
                    )),
                Container(
                  padding: EdgeInsets.only(left: 30, right: 5),
                  alignment: Alignment.centerLeft,
                  child: Material(
                    color: Colors.transparent,
                    child: Text(AppConstants.track_bus,
                        style: TextStyle(
                            fontFamily: AppConstants.FONT_FAMILY,
                            fontSize: AppDimens.appBarTitleSize,
                            fontWeight: FontWeight.w500,
                            color: CommonColors.primaryColor)),
                  ),
                )
              ],
            );
    
            googleMap = GoogleMap(
              rotateGesturesEnabled: true,
              scrollGesturesEnabled: true,
              gestureRecognizers: Set()
                ..add(Factory<PanGestureRecognizer>(() => PanGestureRecognizer()))
                ..add(Factory<ScaleGestureRecognizer>(() => ScaleGestureRecognizer()))
                ..add(Factory<TapGestureRecognizer>(() => TapGestureRecognizer()))
                ..add(Factory<VerticalDragGestureRecognizer>(
                    () => VerticalDragGestureRecognizer())),
              mapType: MapType.normal,
              myLocationEnabled: myLocationEnabled,
              myLocationButtonEnabled: true,
              zoomGesturesEnabled: true,
              markers: markerSet,
              polylines: polylineSet,
              minMaxZoomPreference: MinMaxZoomPreference.unbounded,
              initialCameraPosition: _initialCamera,
              onMapCreated: (GoogleMapController googleMapController)
                 _mapController=googleMapController;
                 _controller.complete(googleMapController);
    
              ,
            );
            final mapView = Container(
              height: double.infinity,
              width: MediaQuery.of(context).size.width,
              child: googleMap,
            );
    
            scaffold = Scaffold(
              appBar: AppBar(
                title: toolbar,
                backgroundColor: CommonColors.appBarColor,
                automaticallyImplyLeading: false,
              ),
              body: Builder(
                builder: (BuildContext context) 
                  mContext = context;
                  return mapView;
                ,
              ),
              floatingActionButton: new Align(
                  alignment: Alignment.bottomRight,
                  child: new FloatingActionButton(
                      child: new Center(
                        child: RotationTransition(
                          turns:
                              Tween(begin: 0.0, end: 1.0).animate(rotationController),
                          child: Icon(
                            Icons.refresh,
                            color: Colors.white,
                          ),
                        ),
                      ),
                      onPressed: () 
                        refreshLocation();
                      )),
            );
          
    
          /*update location and map*/
          initPlatformState() async 
            await _locationService.changeSettings(
                accuracy: LocationAccuracy.HIGH, interval: 1000);
    
            LocationData location;
            // Platform messages may fail, so we use a try/catch PlatformException.
            try 
              bool serviceStatus = await _locationService.serviceEnabled();
              // print("Service status: $serviceStatus");
              if (serviceStatus) 
                _permission = await _locationService.requestPermission();
                //  print("Permission: $_permission");
                if (_permission) 
                  location = await _locationService.getLocation();
    
                  _locationSubscription = _locationService
                      .onLocationChanged()
                      .listen((LocationData result) async 
                    _currentCameraPosition = CameraPosition(
                        target: LatLng(result.latitude, result.longitude), zoom: 14);
                    final GoogleMapController controller = await _controller.future;
                    controller.animateCamera(
                        CameraUpdate.newCameraPosition(_currentCameraPosition));
    
                    if (mounted) 
                      setState(() 
                        _currentLocation = result;
                        if (_currentCameraPosition != null)
                          _initialCamera = _currentCameraPosition;
                      );
                    
                  );
                
               else 
                bool serviceStatusResult = await _locationService.requestService();
                //  print("Service status activated after request: $serviceStatusResult");
                if (serviceStatusResult) 
                  initPlatformState();
                
              
             catch (e) 
              //  print(e);
              if (e.code == 'PERMISSION_DENIED') 
                error = e.message;
               else if (e.code == 'SERVICE_STATUS_ERROR') 
                error = e.message;
              
              location = null;
            
    
            setState(() 
              _startLocation = location;
            );
          
    
          dynamic refreshLocation() async 
            if (_locationSubscription != null) 
              _locationSubscription.cancel();
              await _locationService.changeSettings(
                  accuracy: LocationAccuracy.BALANCED, interval: 1000);
              _locationSubscription =
                  _locationService.onLocationChanged().listen((LocationData result) 
                print("SchoolEasy  Location" + result.longitude.toString());
                Scaffold.of(mContext).showSnackBar(SnackBar(
                  backgroundColor: Colors.blue,
                  content: new Text('Location Updated' + result.longitude.toString()),
                ));
                homeMarker = new Marker(
                  markerId: new MarkerId(homeMarkerId),
                  position: LatLng(result.latitude, result.longitude),
                  icon: icon,
                  infoWindow:
                      InfoWindow(title: "ParentLocation Location", snippet: "snippets"),
                );
    
                if (mounted) 
                  setState(() 
                    _currentLocation = result;
                    //  driverLatLong = new LatLng(result.latitude, result.longitude);
                    markers[homeMarker.markerId] = homeMarker;
                    markerSet = Set<Marker>.of(markers.values);
                    myLocationEnabled = false;
                    rotationController.stop(canceled: true);
                    if (_currentCameraPosition != null)
                      _initialCamera = _currentCameraPosition;
                  );
                
              );
             else 
              refreshLocationDelay();
            
          
    
          /*location permission handling */
    
        /*request permission if not allowed*/
    
          Future requestPermission() async 
            //  print("permission requested");
            Map<PermissionGroup, PermissionStatus> permissions =
                await PermissionHandler()
                    .requestPermissions([PermissionGroup.location]);
          
    
          /*check location service status*/
    
          /*Future<int> checkingServiceStatus() async 
            ServiceStatus serviceStatus =
                await PermissionHandler().checkServiceStatus(PermissionGroup.location);
            return serviceStatus.value;
          
    
          Future<bool> requestRationalPermission() async 
            bool isShown = await PermissionHandler()
                .shouldShowRequestPermissionRationale(PermissionGroup.location);
            return isShown;
          */
    
          Future<int> checkPermission() async 
            PermissionStatus permission = await PermissionHandler()
                .checkPermissionStatus(PermissionGroup.location);
            return permission.value;
          
    
          dynamic fetchDriverLocation() 
            //  print("location fetching");
          
    
          @override
          void dispose() 
            super.dispose();
            if (timer != null) 
              timer.cancel();
            
          
    

【问题讨论】:

您需要输入一些代码,以便我们可以看到您在做什么以及您犯了哪些错误。 hi harunB10 我已经添加了代码,请提前告诉我可能的解决方案,谢谢 【参考方案1】:

这对我来说很好。还为 max、min 函数导入 dart:math。

 import 'dart:math';

 LatLngBounds getBounds(List<Marker> markers) 
    var lngs = markers.map<double>((m) => m.position.longitude).toList();
    var lats = markers.map<double>((m) => m.position.latitude).toList();

    double topMost = lngs.reduce(max);
    double leftMost = lats.reduce(min);
    double rightMost = lats.reduce(max);
    double bottomMost = lngs.reduce(min);

    LatLngBounds bounds = LatLngBounds(
      northeast: LatLng(rightMost, topMost),
      southwest: LatLng(leftMost, bottomMost),
    );

    return bounds;

【讨论】:

以上是关于居中所有标记和折线谷歌地图插件颤振适合屏幕的主要内容,如果未能解决你的问题,请参考以下文章

使用当前位置将折线绘制到目的地,并在谷歌地图上添加标记,标记颤动

仅在设备屏幕的特定部分显示谷歌地图折线

Flutter 谷歌地图插件中的 getbounds

Sencha Touch - 谷歌地图和居中标记

将可拖动标记与折线谷歌地图绑定

android谷歌地图json中的标记