如何使用scopeModel在Flutter中监听firestore文档中的实时更改

import 'package:scoped_model/scoped_model.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

class AppState extends Model {
  Firestore _firestore = Firestore.instance;
  
  // 定义需要监听的数据变量
  List<DocumentSnapshot> _documents = [];

  List<DocumentSnapshot> get documents => _documents;

  // 监听Firestore文档的实时更改
  void listenToDocuments() {
    _firestore.collection('your_collection_path').snapshots().listen((snapshot) {
      _documents = snapshot.documents;
      notifyListeners();
    });
  }
}

import 'package:flutter/material.dart';
import 'package:scoped_model/scoped_model.dart';
import 'app_state.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  final AppState appState = AppState();

  @override
  Widget build(BuildContext context) {
    return ScopedModel<AppState>(
      model: appState,
      child: MaterialApp(
        title: 'Flutter Firestore Demo',
        home: HomeScreen(),
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:scoped_model/scoped_model.dart';
import 'app_state.dart';

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Firestore Demo'),
      ),
      body: ScopedModelDescendant<AppState>(
        builder: (context, child, model) {
          // 根据实时更改的文档渲染UI
          return ListView.builder(
            itemCount: model.documents.length,
            itemBuilder: (context, index) {
              var document = model.documents[index];
              return ListTile(
                title: Text(document.data['title']),
              );
            },
          );
        },
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:scoped_model/scoped_model.dart';
import 'app_state.dart';

class SomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ScopedModelDescendant<AppState>(
      builder: (context, child, model) {
        // 调用listenToDocuments方法开始监听
        model.listenToDocuments();
        
        return Container(
          child: Text('Listening to Firestore documents...'),
        );
      },
    );
  }
}