如何使此代码自动从Firebase获取数据(而无需按浮动的操作按钮)？我是第一次接触Flutter

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

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance.collection('users').snapshots(),
      builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
        if (snapshot.hasError) {
          return Text('Error: ${snapshot.error}');
        }

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

        return ListView(
          children: snapshot.data.docs.map((DocumentSnapshot document) {
            return ListTile(
              title: Text(document.data()['name']),
              subtitle: Text(document.data()['email']),
            );
          }).toList(),
        );
      },
    );
  }
}