why is flutter refusing to connect on localhost:8000 or 127.0.01:8000?

Question

I'm following the Flutter Networking/HTTP tutorial to do a GET request to a server running on my localhost:8000. Visiting my localhost via my browser works fine. This works fine too when I point to any real URL, such as https://example.com, but when I point to https://127.0.0.1:8000 I get an error like " connection refused "

The port in the error above changes each time I reload the app. I looked in the http package code and it doesn't seem like there is a way to specify the port for the URL. How do I point to my localhost please it's my first time with flutter ? PS: i'm running on my phone device , my pc and phone are connected with the same wifi, my network is private.

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

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key key}) : super(key: key);

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

class _MyHomePageState extends State<MyHomePage> {

  static const url = 'http://127.0.0.1:8000/api/membres/';

  // static const url = 'http://10.0.2.2:8000/api/membres/';
  //static const url = 'http://localhost:8000/api/membres/';
  //static const url= "192.168.1...:8000/association/api/membres";
  //static const url = 'https://jsonplaceholder.typicode.com/users';
  Future<List<Map<String, dynamic>>> _future;

  @override
  void initState() {
    super.initState();
    _future = fetch();
  }

  Future<List<Map<String, dynamic>>> fetch() {
    return http
        .get(url)
        .then((response) {
          return response.statusCode == 200
              ? response.body
              : throw 'Error when getting data';
        })
        .then((body) => json.decode(body))
        .then((list) => (list as List).cast<Map<String, dynamic>>());
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Home'),
      ),
      body: RefreshIndicator(
        onRefresh: () async {
          _future = fetch();
          setState(() {});
          return _future;
          },
        child: FutureBuilder<List<Map<String, dynamic>>>(
          future: _future,
          builder: (context, snapshot) {
            if (snapshot.hasError) {
              return Center(
                child: Container(
                  constraints: BoxConstraints.expand(),
                  child: SingleChildScrollView(
                    physics: AlwaysScrollableScrollPhysics(),
                    child: Text(snapshot.error.toString()),),),);}
            if (!snapshot.hasData) {
              return Center(
                child: CircularProgressIndicator(),
              );}
            return ListView.builder(
              itemCount: snapshot.data.length,
              itemBuilder: (BuildContext context, int index) {
                final item = snapshot.data[index];
                return ListTile(
                  title: Text(item['name']),
                  subtitle: Text(item['email']),
                );
              },
            );
          },
        ),
      ),
    );
  }
}

Answer 1

If you are using an Android emulator then localhost on the emulator is not 127.0.0.0 it is 10.0.2.2, so, on Android emulator you need to write https://10.0.2.2:8000, the https://127.0.0.1:8000 will not work on real device too. because localhost means something different on real device.

For more information on how to connect a Flutter app to localhost on emulator or on a real device click on the link Connecting Flutter application to Localhost

Answer 2

You have to keep your mobile phone and computer same network connection.

then pass your url assuming your ip and url is this 192.168.1.102:8000

static const url= "192.168.1.102:8000/association/api/membres";