如何在Flutter中从Firebase获取ListView中的文档和集合？

Question

目前，我想将数据从Cloud Firestore获取到第一页的类别列表和第二页的类别列表详细信息中。

问题是，当我单击“ category1”进入第一页时，它将同时打开两个类别到第二页。

有人在代码错误的地方帮我吗？

firebase database screen shot

  

这是首页代码。

Widget _buildBody(BuildContext context) {
    // return _buildList(context, dummySnapshot);
    return StreamBuilder<QuerySnapshot>(
      stream: Firestore.instance.collection('products').snapshots(),
      builder: (context, snapshot) {
        if (!snapshot.hasData) return LinearProgressIndicator();
        return _buildList(context, snapshot.data.documents);
      },
    );
   }

  Widget _buildList(BuildContext context, List<DocumentSnapshot> snapshot) {
    return ListView(
      padding: const EdgeInsets.only(top: 20.0),
      children: snapshot.map((data) => _buildListItem(context, data)).toList(),
    );
  }

  Widget _buildListItem(BuildContext context, DocumentSnapshot data) {
    final record = Record.fromSnapshot(data);

    return Padding(
      key: ValueKey(record.category),
      padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 8.0),
      child: Container(
        decoration: BoxDecoration(
          border: Border.all(color: Colors.grey),
          borderRadius: BorderRadius.circular(5.0),
        ),
        child: ListTile(
            leading: Icon(Icons.navigate_next),
            title: Text(record.category),
            onTap: () {
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => NewPage(),
                ),
              );
            }),
         ),
    );
  }
}

class Record {
  final String category;
  final DocumentReference reference;

  Record.fromMap(Map<String, dynamic> map, {this.reference})
      : assert(map['category'] != null),
        category = map['category'];

  Record.fromSnapshot(DocumentSnapshot snapshot)
      : this.fromMap(snapshot.data, reference: snapshot.reference);

  @override
  String toString() => "Record<$category>";
}

  

这是第二页代码：

Widget _buildBody(BuildContext context) {
    // return _buildList(context, dummySnapshot);
    return StreamBuilder<QuerySnapshot>(
      stream: Firestore.instance.collection('products').snapshots(),
      builder: (context, snapshot) {
        if (!snapshot.hasData) return LinearProgressIndicator();

        return _buildList(context, snapshot.data.documents);
      },
    );
  }

  Widget _buildList(BuildContext context, List<DocumentSnapshot> snapshot) {
    return ListView(
      padding: const EdgeInsets.only(top: 20.0),
      children: snapshot.map((data) => _buildListItem(context, data)).toList(),
    );
  }

  Widget _buildListItem(BuildContext context, DocumentSnapshot data) {
    final record = Record.fromSnapshot(data);

    return Padding(
      key: ValueKey(record.details),
      padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 8.0),
      child: Container(
        decoration: BoxDecoration(
          border: Border.all(color: Colors.grey),
          borderRadius: BorderRadius.circular(5.0),
        ),
        child: ListTile(
            leading: Icon(Icons.navigate_next),
            title: Text(record.category),
            subtitle: Text(record.details),
            onTap: (){}),
      ),
    );
  }
}

class Record {
  final String details;
  final String category;
  final DocumentReference reference;

  Record.fromMap(Map<String, dynamic> map, {this.reference})
      : assert(map['details'] != null),
        assert(map['category'] != null),
        details = map['details'],
        category = map['category'];

  Record.fromSnapshot(DocumentSnapshot snapshot)
      : this.fromMap(snapshot.data, reference: snapshot.reference);

  @override
  String toString() => "Record<$details:$category>";
}