基于父状态更改的颤动子状态不更新: FlutterFirestore流

import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  Stream<QuerySnapshot> _stream;
  String _parentId;

  @override
  void initState() {
    super.initState();
    _parentId = 'initialParentId'; // 初始父状态值
    _stream = FirebaseFirestore.instance
        .collection('your_collection')
        .where('parentId', isEqualTo: _parentId)
        .snapshots();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        // 父状态的UI组件
        Text('Parent Id: $_parentId'),
        RaisedButton(
          child: Text('Change Parent Id'),
          onPressed: () {
            setState(() {
              _parentId = 'newParentId'; // 更新父状态值
              _stream = FirebaseFirestore.instance
                  .collection('your_collection')
                  .where('parentId', isEqualTo: _parentId)
                  .snapshots();
            });
          },
        ),
        // 子状态的UI组件
        StreamBuilder<QuerySnapshot>(
          stream: _stream,
          builder: (context, snapshot) {
            if (snapshot.hasData) {
              // 处理流数据并更新子状态的UI
              return Text('Child State: ${snapshot.data.docs.length}');
            } else if (snapshot.hasError) {
              return Text('Error: ${snapshot.error}');
            } else {
              return CircularProgressIndicator();
            }
          },
        ),
      ],
    );
  }
}