“构建 function 返回 null。有问题的小部件是：信息构建函数不得返回 null。返回一个空白空间”

Question

What's wrong? I'm beginner in Flutter, and getting this error...

Working with Flutter + Firebase, this is a test to show list of People... I'm learning, sorry for fool mistakes.

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

class info extends StatelessWidget {

  @override

  Widget build(BuildContext context) {

    final content = StreamBuilder(
      stream: FirebaseFirestore.instance.collection('listas').snapshots(),
      builder: (BuildContext context, AsyncSnapshot snapshot) {

        if (!snapshot.hasData) return const Text('Carregando...');

        return ListView.builder(
            itemCount: snapshot.data.documents.length,
            itemBuilder: (BuildContext context, int index){

              DocumentSnapshot doc = snapshot.data.documents[index];

              return ListTile(

                leading: Icon(Icons.ac_unit),
                title: Text(doc['nome']),
                trailing: GestureDetector(
                  onTap: (){

                  },
                ),
              );
            },
        );


      },

    );

  }
}

Answer 1

You need to return the widget you saved in the content variable.