firebase - Flutter/Firebase-文档 ID 未知时如何执行删除文档功能？

Question

我是 Flutter 和开发应用程序的新手，我在其中显示 ListView 中的数据。里面有一个删除图标按钮。我希望应该删除选定的 ListTile 数据。它以List的形式显示数据但不删除。
在我添加了 deleteData() 方法之后。它显示以下错误:

'package:flutter/src/rendering/silver_multi_box_adaptor.dart':Failed assertion: line 263 pos 16: 'child == null || indexOf(child) > index' : is not true.

任何帮助都受到高度赞赏。这是我到目前为止所做的:

class OrderRequestModel extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: UserOrderRequestModel(),
      theme: new ThemeData(
        primarySwatch: Colors.red,
      ),
    );
  }
}

class UserOrderRequestModel extends StatefulWidget {
  @override
  _UserOrderRequestModelState createState() {
    return _UserOrderRequestModelState();
  }
}

class _UserOrderRequestModelState extends State<UserOrderRequestModel> {
  deleteData(docId) {
    Firestore.instance
        .collection('order_tbl')
        .document(docId)
        .delete()
        .catchError((e) {
      print(e);
    });
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: _buildBody(context),
    );
  }
  Stream<QuerySnapshot> getData() async*{
    FirebaseUser firebaseUser = await FirebaseAuth.instance.currentUser();
    yield* Firestore.instance.collection('order_tbl').orderBy('timestamp', descending: true).snapshots();
  }

  Widget _buildBody(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
      stream: getData(),
      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: 5.0),
      children: snapshot.map((data) => _buildListItem(context, data)).toList(),
    );
  }

  Widget _buildListItem(BuildContext context, DocumentSnapshot data) {
    final record = Record.fromSnapshot(data);
    String _string =getTimeDifferenceFromNow(record.timestamp.toDate());
    return Padding(
      key: ValueKey(record.animal),
      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: new ListTile(
            title: new Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: <Widget>[
                new Text(
                  "${record.quantity} kg ${record.animal} - ${record.mobile}",
                  style: new TextStyle(fontWeight: FontWeight.bold, color: Colors.black),
                ),
                new Text(
                  _string,
                  style: new TextStyle(color: Colors.grey, fontSize: 12.0),
                ),
              ],
            ),
            trailing: IconButton(
              icon: Icon(Icons.delete_forever),
              onPressed: () => deleteData(data.documentID),
            ),

            subtitle: new Container(
              padding: const EdgeInsets.only(top: 5.0),
              child: new Text(
                record.address,
                style: new TextStyle(color: Colors.red, fontSize: 12.0,),
              ),
            ),
          ),
      ),
    );
  }
}

Answer 1

删除单个文档:

var collection = FirebaseFirestore.instance.collection('users');
await collection.doc('document_id').delete();

删除部分文件:

var collection = FirebaseFirestore.instance.collection('users');
var snapshot = await collection.where('age', isGreaterThan: 20).get();
for (var doc in snapshot.docs) {
 await doc.reference.delete();
}

删除所有文件:

var collection = FirebaseFirestore.instance.collection('users');
var snapshot = await collection.get();
for (var doc in snapshot.docs) {
  await doc.reference.delete();
}