使用颤振和Firebase按位置显示附近位置

我正在开发一个应用程序使用颤振和Firebase，类似于一个食品递送应用程序。所以，我的问题是，你知道像优步这样的应用程序，你可以选择你的位置，然后应用程序显示你附近的餐馆？这就是我想要达到的目标

我有一个餐馆应用程序，它可以设置位置，我正在firebase上的一个集合中添加这些信息，带有geohash坐标。在终端用户应用程序中，我想在屏幕上显示餐厅名称、图片和菜单等

我所取得的成就：

final Stream<QuerySnapshot> _usersStream =
      FirebaseFirestore.instance.collection('Companies').snapshots();

Container(
            child: StreamBuilder(
              stream: _usersStream,
              builder: (BuildContext context,
                  AsyncSnapshot<QuerySnapshot> snapshot) {
                if (snapshot.hasError) {
                  return Text('Something went wrong');
                }
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return Text("Loading");
                }
                print(snapshot.data);
                return new ListView(
                  children: snapshot.data.docs.map((DocumentSnapshot document) {
                    return new ListTile(
                      title: new Text(document.data()['companyName']),
                      subtitle: new Image.network(document.data()['url']),
                    );
                  }).toList(),
                );
              },
            ),
          ),

Stream showNearbyCompanies() async* {
    var pos = await location.getLocation();

    GeoFirePoint point =
        geo.point(latitude: pos.latitude, longitude: pos.longitude);

    double distance = 30;

    double lat = 0.023323826086956514;
    double lon = 0.02926080000000002776;

    double lowerLat = point.latitude - (lat * distance);
    double lowerLon = point.longitude - (lon * distance);

    double greaterLat = point.latitude + (lat * distance);
    double greaterLon = point.longitude + (lon * distance);

    GeoPoint lesserGeoPoint = GeoPoint(lowerLat, lowerLon);
    GeoPoint greaterGeoPoint = GeoPoint(greaterLat, greaterLon);

    Stream<QuerySnapshot> query = _firebaseFirestore
        .collection("Companies")
        .where("location", isGreaterThan: lesserGeoPoint)
        .where("location", isLessThan: greaterGeoPoint)
        .snapshots();

    yield query;
  }

我可以在没有位置部分的情况下实现这一点。因此，目前，每个餐厅都将显示在最终用户应用程序中

这是函数：

final Stream<QuerySnapshot> _usersStream =
      FirebaseFirestore.instance.collection('Companies').snapshots();

Container(
            child: StreamBuilder(
              stream: _usersStream,
              builder: (BuildContext context,
                  AsyncSnapshot<QuerySnapshot> snapshot) {
                if (snapshot.hasError) {
                  return Text('Something went wrong');
                }
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return Text("Loading");
                }
                print(snapshot.data);
                return new ListView(
                  children: snapshot.data.docs.map((DocumentSnapshot document) {
                    return new ListTile(
                      title: new Text(document.data()['companyName']),
                      subtitle: new Image.network(document.data()['url']),
                    );
                  }).toList(),
                );
              },
            ),
          ),

Stream showNearbyCompanies() async* {
    var pos = await location.getLocation();

    GeoFirePoint point =
        geo.point(latitude: pos.latitude, longitude: pos.longitude);

    double distance = 30;

    double lat = 0.023323826086956514;
    double lon = 0.02926080000000002776;

    double lowerLat = point.latitude - (lat * distance);
    double lowerLon = point.longitude - (lon * distance);

    double greaterLat = point.latitude + (lat * distance);
    double greaterLon = point.longitude + (lon * distance);

    GeoPoint lesserGeoPoint = GeoPoint(lowerLat, lowerLon);
    GeoPoint greaterGeoPoint = GeoPoint(greaterLat, greaterLon);

    Stream<QuerySnapshot> query = _firebaseFirestore
        .collection("Companies")
        .where("location", isGreaterThan: lesserGeoPoint)
        .where("location", isLessThan: greaterGeoPoint)
        .snapshots();

    yield query;
  }

最终流\u用户流=
FirebaseFirestore.instance.collection（'companys'）.snapshots（）；

这是我用来显示收藏的列表视图：

final Stream<QuerySnapshot> _usersStream =
      FirebaseFirestore.instance.collection('Companies').snapshots();

Container(
            child: StreamBuilder(
              stream: _usersStream,
              builder: (BuildContext context,
                  AsyncSnapshot<QuerySnapshot> snapshot) {
                if (snapshot.hasError) {
                  return Text('Something went wrong');
                }
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return Text("Loading");
                }
                print(snapshot.data);
                return new ListView(
                  children: snapshot.data.docs.map((DocumentSnapshot document) {
                    return new ListTile(
                      title: new Text(document.data()['companyName']),
                      subtitle: new Image.network(document.data()['url']),
                    );
                  }).toList(),
                );
              },
            ),
          ),

Stream showNearbyCompanies() async* {
    var pos = await location.getLocation();

    GeoFirePoint point =
        geo.point(latitude: pos.latitude, longitude: pos.longitude);

    double distance = 30;

    double lat = 0.023323826086956514;
    double lon = 0.02926080000000002776;

    double lowerLat = point.latitude - (lat * distance);
    double lowerLon = point.longitude - (lon * distance);

    double greaterLat = point.latitude + (lat * distance);
    double greaterLon = point.longitude + (lon * distance);

    GeoPoint lesserGeoPoint = GeoPoint(lowerLat, lowerLon);
    GeoPoint greaterGeoPoint = GeoPoint(greaterLat, greaterLon);

    Stream<QuerySnapshot> query = _firebaseFirestore
        .collection("Companies")
        .where("location", isGreaterThan: lesserGeoPoint)
        .where("location", isLessThan: greaterGeoPoint)
        .snapshots();

    yield query;
  }

容器(
孩子：StreamBuilder(
流：_usersStream，
生成器：（BuildContext上下文，
异步快照（快照）{
if（snapshot.hasError）{
返回文本（“出错”）；
}
if（snapshot.connectionState==connectionState.waiting）{
返回文本（“加载”）；
}
打印（快照数据）；
返回新的ListView(
子项：snapshot.data.docs.map（（DocumentSnapshot文档）{
返回新的ListTile(
标题：新文本（document.data（）['companyName']），
字幕：新建Image.network（document.data（）['url']），
);
}).toList（），
);
},
),
),

有没有人知道我需要更改什么，以便我可以使用设置的半径进行查询？我知道有一些方法，比如“.where（'field'，isLowerThan:x）”，但我无法让它工作

另外，这里是我的firebase的屏幕截图：

final Stream<QuerySnapshot> _usersStream =
      FirebaseFirestore.instance.collection('Companies').snapshots();

Container(
            child: StreamBuilder(
              stream: _usersStream,
              builder: (BuildContext context,
                  AsyncSnapshot<QuerySnapshot> snapshot) {
                if (snapshot.hasError) {
                  return Text('Something went wrong');
                }
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return Text("Loading");
                }
                print(snapshot.data);
                return new ListView(
                  children: snapshot.data.docs.map((DocumentSnapshot document) {
                    return new ListTile(
                      title: new Text(document.data()['companyName']),
                      subtitle: new Image.network(document.data()['url']),
                    );
                  }).toList(),
                );
              },
            ),
          ),

Stream showNearbyCompanies() async* {
    var pos = await location.getLocation();

    GeoFirePoint point =
        geo.point(latitude: pos.latitude, longitude: pos.longitude);

    double distance = 30;

    double lat = 0.023323826086956514;
    double lon = 0.02926080000000002776;

    double lowerLat = point.latitude - (lat * distance);
    double lowerLon = point.longitude - (lon * distance);

    double greaterLat = point.latitude + (lat * distance);
    double greaterLon = point.longitude + (lon * distance);

    GeoPoint lesserGeoPoint = GeoPoint(lowerLat, lowerLon);
    GeoPoint greaterGeoPoint = GeoPoint(greaterLat, greaterLon);

    Stream<QuerySnapshot> query = _firebaseFirestore
        .collection("Companies")
        .where("location", isGreaterThan: lesserGeoPoint)
        .where("location", isLessThan: greaterGeoPoint)
        .snapshots();

    yield query;
  }

编辑：

final Stream<QuerySnapshot> _usersStream =
      FirebaseFirestore.instance.collection('Companies').snapshots();

Container(
            child: StreamBuilder(
              stream: _usersStream,
              builder: (BuildContext context,
                  AsyncSnapshot<QuerySnapshot> snapshot) {
                if (snapshot.hasError) {
                  return Text('Something went wrong');
                }
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return Text("Loading");
                }
                print(snapshot.data);
                return new ListView(
                  children: snapshot.data.docs.map((DocumentSnapshot document) {
                    return new ListTile(
                      title: new Text(document.data()['companyName']),
                      subtitle: new Image.network(document.data()['url']),
                    );
                  }).toList(),
                );
              },
            ),
          ),

Stream showNearbyCompanies() async* {
    var pos = await location.getLocation();

    GeoFirePoint point =
        geo.point(latitude: pos.latitude, longitude: pos.longitude);

    double distance = 30;

    double lat = 0.023323826086956514;
    double lon = 0.02926080000000002776;

    double lowerLat = point.latitude - (lat * distance);
    double lowerLon = point.longitude - (lon * distance);

    double greaterLat = point.latitude + (lat * distance);
    double greaterLon = point.longitude + (lon * distance);

    GeoPoint lesserGeoPoint = GeoPoint(lowerLat, lowerLon);
    GeoPoint greaterGeoPoint = GeoPoint(greaterLat, greaterLon);

    Stream<QuerySnapshot> query = _firebaseFirestore
        .collection("Companies")
        .where("location", isGreaterThan: lesserGeoPoint)
        .where("location", isLessThan: greaterGeoPoint)
        .snapshots();

    yield query;
  }

这是餐厅应用程序上的代码，我正在使用Google Places API存储地质点：

Future<Null> displayPrediction(Prediction p) async {
    if (p != null) {
      PlacesDetailsResponse detail =
          await _places.getDetailsByPlaceId(p.placeId);

      double lat = detail.result.geometry.location.lat;
      double lng = detail.result.geometry.location.lng;

      GeoPoint point = new GeoPoint(lat, lng);

      final CollectionReference companies =
          _firebaseFirestore.collection("Companies");
      final String uid = _firebaseAuth.currentUser.uid;
      await companies.doc(uid).update({'location': point});
      final result = await companies.doc(uid).get();
      return result.data()["location"];
    }
  }

未来显示预测（预测p）异步{
如果（p！=null）{
位置细节响应细节=
等待地点。getDetailsByPlaceId（p.placeId）；
双lat=detail.result.geometry.location.lat；
双液化天然气=详图.result.geometry.location.lng；
地质点=新的地质点（纬度、液化天然气）；
最终收集参考公司=
_firebaseFirestore.集合（“公司”）；
最终字符串uid=\u firebaseAuth.currentUser.uid；
wait companys.doc（uid）.update（{'location'：point}）；
最终结果=wait companys.doc（uid.get（）；
返回result.data（）[“location”]；
}
}

我试图使用经度和纬度的代码片段：

final Stream<QuerySnapshot> _usersStream =
      FirebaseFirestore.instance.collection('Companies').snapshots();

Container(
            child: StreamBuilder(
              stream: _usersStream,
              builder: (BuildContext context,
                  AsyncSnapshot<QuerySnapshot> snapshot) {
                if (snapshot.hasError) {
                  return Text('Something went wrong');
                }
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return Text("Loading");
                }
                print(snapshot.data);
                return new ListView(
                  children: snapshot.data.docs.map((DocumentSnapshot document) {
                    return new ListTile(
                      title: new Text(document.data()['companyName']),
                      subtitle: new Image.network(document.data()['url']),
                    );
                  }).toList(),
                );
              },
            ),
          ),

Stream showNearbyCompanies() async* {
    var pos = await location.getLocation();

    GeoFirePoint point =
        geo.point(latitude: pos.latitude, longitude: pos.longitude);

    double distance = 30;

    double lat = 0.023323826086956514;
    double lon = 0.02926080000000002776;

    double lowerLat = point.latitude - (lat * distance);
    double lowerLon = point.longitude - (lon * distance);

    double greaterLat = point.latitude + (lat * distance);
    double greaterLon = point.longitude + (lon * distance);

    GeoPoint lesserGeoPoint = GeoPoint(lowerLat, lowerLon);
    GeoPoint greaterGeoPoint = GeoPoint(greaterLat, greaterLon);

    Stream<QuerySnapshot> query = _firebaseFirestore
        .collection("Companies")
        .where("location", isGreaterThan: lesserGeoPoint)
        .where("location", isLessThan: greaterGeoPoint)
        .snapshots();

    yield query;
  }

Stream shownnearbycompanies（）异步*{
var pos=await location.getLocation（）；
地火点=
地理点（纬度：位置纬度，经度：位置经度）；
双倍距离=30；
双板条=0.023323826086956514；
双lon=0.0292608000002776；
双下纬度=点纬度-（纬度*距离）；
双下经度=点经度-（经度*距离）；
双大纬度=点纬度+（纬度*距离）；
double greaterLon=点经度+（经度*距离）；
地质点lesserGeoPoint=地质点（lowerLat，lowerLon）；
地质点greaterGeoPoint=地质点（greaterLat，greaterLon）；
流查询=\u firebaseFirestore
.收款（“公司”）
.where（“位置”，大于：lesserGeoPoint）
.其中（“位置”，小于：greaterGeoPoint）
.快照（）；
产量查询；
}

我在屏幕截图中没有看到任何geohash，也没有在代码中看到任何对geohash的过滤。你确定你遵循了上的文档吗？在你的问题中，你说“使用geohash坐标”，但就我所见，屏幕截图中没有geohash，代码中也没有。我建议学习我链接的文档，因为它以一种比我们在这里做得更好的方式概括了这些步骤。嗨！我会使用地理哈希，因为使用纬度和经度不允许您查询@FrankvanPuffelen共享的文档中解释的结果。然后，要查询GeoHash，必须选择当前设备位置和半径并跟随。另外，请您提供一个片段，说明您是如何通过radius进行查询的？您的问题已标记为GeoFirestore-所以。。。你为什么不用它？这使得这项任务变得微不足道。还有，你已经问过这个问题了。你为什么一遍又一遍地问同一个问题？请不要一遍又一遍地发布同一个问题。它最终可能会让你被禁止。发布一个问题，当评论进来并要求更多信息时，不断完善它。例如，我在上面问了一个特定的问题，而您没有解决它或添加更多的细节。这又是一个问题：您已将问题标记为，但没有代码指示您正在使用它。GeoFirestore使此任务变得微不足道，并且完全按照您的要求执行。一行代码返回给定半径内的所有餐厅。你为什么不用它？