ListView.Builder不工作

Question

在尝试实现flutter-firebase时，listview.builder未能显示！

注意，当我尝试在没有listview.builder的情况下显示第一个元素时，它工作得很好，即错误只出现在与这段代码相关的地方：

return ListView.builder(
    itemCount: snapshot.data.documents.length,
    padding: const EdgeInsets.only(top: 10.0),
    itemExtent: 25.0,
    itemBuilder: (context, index) {
    DocumentSnapshot ds = snapshot.data.documents[index];
    return Text(" ${ds['name']} ${ds['vote']}");
});

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

void main() => runApp(MyApp(
  textInput: Text("Text Widget"),
));

class MyApp extends StatefulWidget {
  final Widget textInput;
  MyApp({this.textInput});

  @override
  State<StatefulWidget> createState() => MyAppState();
}

class MyAppState extends State<MyApp> {
  bool checkBoxValue = false;
  @override
  Widget build(BuildContext ctxt) {
    return new MaterialApp(
      home: SafeArea(
        child: Scaffold(
            body: new Center(
                child: new Column(
                  children: <Widget>[
                    widget.textInput,
                    Checkbox(
                        value: checkBoxValue,
                        onChanged: (bool newValue){
                          setState(() {
                            checkBoxValue = newValue;
                          });
                        }
                    ),
                    StreamBuilder(
                        stream: Firestore.instance.collection('baby').snapshots(),
                        builder: (context, snapshot) {
                          if (!snapshot.hasData) return const Text('Loading...');

                           //   DocumentSnapshot ds = snapshot.data.documents[0];
                           //   return new Text(" ${ds['name']} ${ds['vote']}");

                          // When i try to replace the above code by the below it fails!
                               return ListView.builder(
                                itemCount: snapshot.data.documents.length,
                                padding: const EdgeInsets.only(top: 10.0),
                                itemExtent: 25.0,
                                itemBuilder: (context, index) {
                                DocumentSnapshot ds = snapshot.data.documents[index];
                                return Text(" ${ds['name']} ${ds['vote']}");
                              });
                           // End of the ListView builder that fails!

                        }),
                  ],
                ))),
      ),
    );
  }
}

Answer 1

将StreamBuilder包装成展开的。因为它位于列中