从 firebase firestore 集合中获取文档并添加 List<Map<String, dynamic>>

Question

我如何从 firebase firestore 集合中获取文档并将它们添加到 _allUsers 而不是现有值中，我最近在升级 flutter 后遇到了这个问题，在此之前一切正常，我试图查看文档，但我无法解决它

List<listCard> orderWidgets = [];

 void get_allUsers(){
   FirebaseFirestore.instance
    .collection('users')
    .get()
    .then((QuerySnapshot querySnapshot) {
        querySnapshot.docs.forEach((doc) {
             final orderName = doc['name'];
  final orderAddress = doc['address'];
  final orderTime = doc['time'];
 
   final orderWidgetshape = Card(
    name: orderName ?? "default value",
     location: orderAddress ?? "default value",
     time: orderTime ?? "default value",
    
   );
   orderWidgets.add(orderWidgetshape);
        });
    });
}

列表

final List<Map<String, dynamic>> _allUsers = [
  {"id": 1, "name": "Andy", "date": '2022-01-25 10:14'},
  {"id": 2, "name": "Aragon", "date": '2022-01-02 10:14'},
  {"id": 3, "name": "Bob", "date": '2022-01-20 10:14'},
  {"id": 4, "name": "Barbara", "date": '2022-01-20 10:14'},
  {"id": 5, "name": "Candy", "date": '2022-01-18 10:14'},
  {"id": 6, "name": "Colin", "date": '2022-01-24 10:14'},
  {"id": 7, "name": "Audra", "date": '2022-01-23 10:14'},
  {"id": 8, "name": "Banana", "date": '2022-01-22 10:14'},
  {"id": 9, "name": "Caversky", "date": '2022-01-30 10:14'},
  {"id": 10, "name": "Becky", "date": '2022-01-28 10:14'},
];

// This list holds the data for the list view
List<Map<String, dynamic>> _foundUsers = []; 



    void initState() {
        super.initState();
        setState(() {
          _foundUsers = _allUsers;
        });
      }

列表视图和过滤按钮

       @override
  Widget build(BuildContext context) {
    final orientation = MediaQuery.of(context).orientation;

    return Scaffold(
      appBar: AppBar(
        elevation: 0.0,
        bottomOpacity: 0.0,
      ),
      drawer: AppDrawer(),
      body: ListView(
        children: [
          Row(mainAxisSize: MainAxisSize.max, children: [
          
            Expanded(
              child: Container(
                height: orientation == Orientation.portrait ? 70 : 70,
                // width: 170.0,
                child: ReusableFilterChipHomeVisits(
                  onPress: () {
                    setState(() {
                     
                      _foundUsers = _allUsers.where((element) {
                        DateTime tempDate = new DateFormat("yyyy-MM-ddhh:mm").parse(element['date'] ); 

                        return now_2days.isBefore(tempDate);
                      }).toList();

                      selectedButton = Btn.last2day;
                    });
                  },
                  cardChild: Text(
                    'آخر يومين',
                    textAlign: TextAlign.center,
                    style: TextStyle(
                      color: selectedButton == Btn.last2day
                          ? KWhiteColor
                          : KInActiveColor,
                      fontSize: 19.0,
                      fontFamily: 'Cairo-Italic',
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                  colour: selectedButton == Btn.last2day
                      ? KInActiveColor
                      : KWhiteColor,
                ),
              ),
            ),
          
          SizedBox(height: 25.0),
        
         StreamBuilder<QuerySnapshot>(
                stream: _firestore.collection('visithomeorders').snapshots(),
               builder:  (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
                 if (snapshot.hasError) {
                   return Center(
                     child: Container(
                       child: CircularProgressIndicator(
                         backgroundColor: KInActiveColor,
                       ),
                     ),
                   );
                 }

                 if (snapshot.connectionState == ConnectionState.waiting) {
                   return Text("Loading");
                 }

                 return SingleChildScrollView(
                   child: Column(
                       children: [
                         _foundUsers.isNotEmpty
                             ? ListView.builder(
                           physics: NeverScrollableScrollPhysics(),
                           shrinkWrap: true,
                           scrollDirection: Axis.vertical,
                           itemCount: _foundUsers.length,
                           itemBuilder: (context, index) =>
                               Card(
                                 key: ValueKey(_foundUsers[index]["id"]),
                                 color: Colors.amberAccent,
                                 elevation: 4,
                                 margin: const EdgeInsets.symmetric(
                                     vertical: 10),
                                 child: ListTile(
                                   leading: Text(
                                     _foundUsers[index]["id"].toString(),
                                     style: const TextStyle(fontSize: 24),
                                   ),
                                   title: Text(_foundUsers[index]['name']),
                                   subtitle: Text(
                                       '${_foundUsers[index]["date"]
                                           .toString()}'),
                                 ),
                               ),
                         )
                             : const Text(
                           'No results found',
                           style: TextStyle(fontSize: 24),
                         ),
                       ]
                   ),
                 );
               })
        ],
      ),
      // bottomNavigationBar: MyBottomBar(),
    );
  }
}

Answer 1

我找到了答案：我按照文档中的说明使用了此功能

get_allUsers(){
   FirebaseFirestore.instance
       .collection('visithomeorders')
       .get()
       .then((QuerySnapshot querySnapshot) {
     querySnapshot.docs.forEach((doc) {
       _allUsers.add(doc.data());
     });
   });
}

然后

void initState() {
    super.initState();
    setState(() {
      _foundUsers = _allUsers;
      get_allUsers();
    });
  }

最后我使用了 Streambuilder 中的列表

   StreamBuilder<QuerySnapshot>(
                    stream: _firestore.collection('visithomeorders').snapshots(),
                   builder:  (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
                     if (snapshot.hasError) {
                       return Center(
                         child: Container(
                           child: CircularProgressIndicator(
                             backgroundColor: KInActiveColor,
                           ),
                         ),
                       );
                     }
    
                     if (snapshot.connectionState == ConnectionState.waiting) {
                       return Text("Loading");
                     }
    
                     return SingleChildScrollView(
                       child: Column(
                           children: [
                             _foundUsers.isNotEmpty
                                 ? ListView.builder(
                               physics: NeverScrollableScrollPhysics(),
                               shrinkWrap: true,
                               scrollDirection: Axis.vertical,
                               itemCount: _foundUsers.length,
                               itemBuilder: (context, index) =>
                                   listCard(
                                           name: _foundUsers[index]['name'] ?? "default value",
                                           time: _foundUsers[index]['time'] ?? "default value",
                                           date: _foundUsers[index]['date'] ?? "default value",
                                         )
                                 
                             )
                                 : const Text(
                               'No results found',
                               style: TextStyle(fontSize: 24),
                             ),
                           ]
                       ),
                     );
               })

从 firebase firestore 集合中获取文档并添加 List<Map<String, dynamic>>

get documents from firebase firestore collection and add List<Map<String, dynamic>>

firebase

flutter

firestorter