SignalR disconnects when put iOS app in background

[nayanAubie]

• I followed the exact code mentioned in the example project.
• When I put the iOS app in the background for around 30 seconds, SignalR disconnects automatically and when I back the app in the foreground again, it shows the log of Reconnecting and Reconnected.
• I've used an iPhone 11 with the release mode app.

[umairali4433]

i was facing the same issue no one helped so what i did was i just created listner for every 3 second if my hub is disconnected then do reconnect sample code:
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:signalr_core/signalr_core.dart';

void main() {
runApp(MyApp());
}

class MyApp extends StatelessWidget {
@OverRide
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('HubConnection Status Checker'),
),
body: Center(
child: HubConnectionStatusChecker(),
),
),
);
}
}

class HubConnectionStatusChecker extends StatefulWidget {
@OverRide
_HubConnectionStatusCheckerState createState() => _HubConnectionStatusCheckerState();
}

class _HubConnectionStatusCheckerState extends State {
late HubConnection _hubConnection;
late Timer _timer;

@OverRide
void initState() {
super.initState();

// Initialize your HubConnection here
_hubConnection = HubConnectionBuilder()
  .withUrl('your_hub_connection_url')
  .build();

// Start checking the connection status every second
_timer = Timer.periodic(Duration(seconds: 1), (timer) {
  // Check the connection status
  if (_hubConnection.state == HubConnectionState.Connected) {
    print('HubConnection is connected');
  } else {
    print('HubConnection is not connected');
    // Optionally, try to start the connection again
    // _hubConnection.start();
  }
});

}

@OverRide
void dispose() {
// Cancel the timer and dispose the HubConnection
_timer.cancel();
_hubConnection.stop();
super.dispose();
}

@OverRide
Widget build(BuildContext context) {
return Text('Checking HubConnection status...');
}
}

and it worked perfectly now i am not facing this issue

[os01ri]

facing the same issue in android devices

[xaldarof]

facing the same issue in android and iOS devices

[monake1479]

I was facing the same issue but even worse, because my hub connection was trying to refresh token by provided method and that request failed also. And because of that my app was rolling back to initial screen because user was sign out.
So I implemented AppLifecycleState listener to disconnect from hub where app is in background state and connect again when app was again in resume state.

import 'package:flutter/scheduler.dart';

class MyAppLifecycleListener extends StatefulWidget {
  const MyAppLifecycleListener({
    super.key,
  });

  @override
  State<MyAppLifecycleListener> createState() => _MyAppLifecycleListenerState();
}

class _MyAppLifecycleListenerState extends State<MyAppLifecycleListener> {
  late final AppLifecycleListener _listener;
  late AppLifecycleState? _lifecycleState;

  @override
  void initState() {
    super.initState();
    _lifecycleState = SchedulerBinding.instance.lifecycleState;
    _listener = AppLifecycleListener(
      onPause: () {
        // We need to pause hub connection here, because app is going to background

        // Call your method to pause hub connection

      },
      onResume: () {
        // We need to resume hub connection here if it was paused.
        // You need to check that in you hub connection.
        // Because when app is in a background for a short time, onPause may not be called.

        // Call your method to resume hub connection
      },
      onStateChange: _handleStateChange,
    );
  }

  void _handleStateChange(AppLifecycleState state) {
    setState(() {
      _lifecycleState = state;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Container(child:Text('Your app'));
  }

  @override
  void dispose() {
    _lifecycleState = null;
    _listener.dispose();
    super.dispose();
  }
}

And that solution worked for me. 👍