从Flutter的Firestore收藏中获取全部 [英] Get all from a Firestore collection in Flutter

问题描述

我在项目中设置了Firestore。我创建了名为 categories 的新集合。在这个集合中，我创建了三个带有uniq id的文档。现在，我想在Flutter应用程序中获取此集合，因此我创建了 CollectionReference ：

I set up Firestore in my project. I created new collection named categories. In this collection I created three documents with uniq id. Now I want to get this collection in my Flutter application so I created CollectionReference:

Firestore.instance.collection('categories')

但我不知道接下来会发生什么。

but I don't know what next.

我正在使用此插件 firebase_firestore：0.0.1 + 1

推荐答案

使用 StreamBuilder

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

class ExpenseList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new StreamBuilder<QuerySnapshot>(
        stream: Firestore.instance.collection("expenses").snapshots,
        builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
          if (!snapshot.hasData) return new Text("There is no expense");
          return new ListView(children: getExpenseItems(snapshot));
        });
  }

  getExpenseItems(AsyncSnapshot<QuerySnapshot> snapshot) {
    return snapshot.data.documents
        .map((doc) => new ListTile(title: new Text(doc["name"]), subtitle: new Text(doc["amount"].toString())))
        .toList();
  }
}

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