在StreamBuilder中检索子集合(Flutter) [英] Retrieve Subcollection in StreamBuilder (Flutter)

问题描述

在Flutter应用程序中有一个StreamBuilder，可用于检索文档中的数据:

I have a StreamBuilder in my Flutter app which I can use to retrieve data in a document:

class Example extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
  ListView.builder(
  itemCount: aCollection.length,
  itemBuilder: (BuildContext context, int index) {
  return Card(
    child: Row(
      children: <Widget>[
         Text(aCollection[index].data['area']), // Return Area

如何检索子集合中的数据?类似于以下内容:

How can I retrieve data in a Subcollection? Something along the lines of:

aCollection[index]['aDoc']**[aSubCollection]**.data['field']

我不确定语法是否正确-如果有人可以将我指向正确的方向，那就太好了！

I'm not sure of the correct syntax - would be great if someone can point me in the right direction!

数据库示例屏幕快照:

Database Example Screenshot:

推荐答案

如果aCollection[index]是 DocumentSnapshot ，则可以使用aCollection[index].reference.collection("aSubCollection")将CollectionReference分配给子集合.

If aCollection[index] is a DocumentSnapshot, then you can get a CollectionReference to a subcollection with aCollection[index].reference.collection("aSubCollection").

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