Question

我在Geting data from mysql to StreamBuilder Flutter的Flutter应用程序遇到了问题在这里how to force the server to respond as json 现在一切都很好，但是StreamBuilder仅传递了表中的第一行，我该怎么办。

最新的抖动代码：-

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'dart:async';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Server',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.pink,
      ),
      home: MyHomePage(title: 'Flutter Server App'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  StreamController<Map> _streamController = StreamController<Map>();
  Timer _timer;

  Future getData() async {
    var url = 'https://milk-white-reveille.000webhostapp.com/get.php';
    http.Response response = await http.get(url);
    Map data = json.decode(response.body);
    //Add your data to stream
    _streamController.add(data);
  }

  @override
  void initState() {
    super.initState();
    getData();
    //Check the server every 5 seconds
    _timer = Timer.periodic(Duration(seconds: 5), (timer) => getData());
  }

  @override
  void dispose() {
    //cancel the timer
    if (_timer.isActive) _timer.cancel();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
        centerTitle: true,
      ),
      body: StreamBuilder(
        stream: _streamController.stream,
        builder: (BuildContext context, AsyncSnapshot snapshot) {
          if (!snapshot.hasData) return Text('Loading...');
            return ListView(
              children: [
                ListTile(
                  title: Text(snapshot.data['title']),
                  subtitle: Text(snapshot.data['type']),
                ),
              ],
            );
        },
      ),
    );
  }
}

最新的PHP代码：-

get.php

<?php
header("Content-type: application/json; charset=utf-8");
require_once('db.php');
$query = 'SELECT * FROM `flutter` WHERE 1';
$stm = $db->prepare($query);
$stm->execute();
$row = $stm->fetch(PDO::FETCH_ASSOC);
echo json_encode($row);
$row = $stm->fetch(PDO::FETCH_ASSOC);
echo json_encode($row);

db.php

<?php

$dns = 'mysql:host=localhost;dbname=id13424627_flutter';
$user = 'id13424627_flutter_app';
$pass = 'Flutter_maen12';

try{
  $db = new PDO ($dns, $user, $pass);
  
}catch( PDOException $e){
    $error = $e->getMessage();
    echo $error;
}

Answer 1

您应该在服务器端进行的更改；

<?php
header("Content-type: application/json; charset=utf-8");
require_once('db.php');
$query = 'SELECT * FROM `flutter`';
$stm = $db->prepare($query);
$stm->execute();
$rows = $stm->fetchAll(PDO::FETCH_ASSOC);
echo json_encode($rows);

您的颤动代码；

class _MyHomePageState extends State<MyHomePage> {
  StreamController<List> _streamController = StreamController<List>();
  Timer _timer;

  Future getData() async {
    var url = 'https://milk-white-reveille.000webhostapp.com/get.php';
    http.Response response = await http.get(url);
    List data = json.decode(response.body);

    //Add your data to stream
    _streamController.add(data);
  }

  @override
  void initState() {
    getData();

    //Check the server every 5 seconds
    _timer = Timer.periodic(Duration(seconds: 5), (timer) => getData());

    super.initState();
  }

  @override
  void dispose() {
    //cancel the timer
    if (_timer.isActive) _timer.cancel();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("widget.title"),
        centerTitle: true,
      ),
      body: StreamBuilder<List>(
        stream: _streamController.stream,
        builder: (BuildContext context, AsyncSnapshot snapshot) {
          if (snapshot.hasData)
            return ListView(
              children: [
                for (Map document in snapshot.data)
                  ListTile(
                    title: Text(document['title']),
                    subtitle: Text(document['type']),
                  ),
              ],
            );
          return Text('Loading...');
        },
      ),
    );
  }
}

Answer 2

检查$query = 'SELECT * FROM 颤动 WHERE 1';

WHERE 1

删除以显示或更改为 WHERE id='whatever you want to display only'

将数据从mysql传递到flutter小部件

2 个答案: