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Android 8 receive of stop receiving media buttons events

I have a service that listens to media buttons, but I only want to listen to those when my service is running since I have a button on the UI to start/stop the service.
How can I achieve the following two actions:
On MyService start-up, start receiving media button events to com.myApp/MyService.
On MyService end, stop receiving media button events in com.myApp/MyService.
The related logs are the following:
D MediaSessionService: Sending KeyEvent { action=ACTION_DOWN, keyCode=KEYCODE_HEADSETHOOK, scanCode=226, metaState=0, flags=0x8, repeatCount=0, eventTime=13258317, downTime=13258317, deviceId=4, source=0x101 } to com.myApp/MyService (userId=0)
Note:
I found out that I can start receiving media events after my app started to play audio. This is however not ideal, since I don't want to play audio in my app. (I am only using media events in order to trigger voice recognition)
After I played audio, my service is apparently the default media receiver. This means that when a media button is pressed, my service get instantiated, does nothing, and get destroyed. This is not an idea behavior for the end user since my app ends up 'stealing' these events that could potentially be handled by something else.
Overriding OnStartCommand() in my service does not help
Calling SetMediaButtonReceiver on the MediaSession does not help either
Using a BroadcastReceiver with the intent "android.intent.action.MEDIA_BUTTON" registered in the AudioManager does not work either
Relevant code (in C#, I am on Xamarin.Forms, but that should not have any impact on the way to achieve this)
public class MediaSessionCompatCallback : MediaSessionCompat.Callback
{
public Func<Intent, bool> MediaButtonEvent { get; set; }
public override bool OnMediaButtonEvent(Intent mediaButtonEvent) => MediaButtonEvent?.Invoke(mediaButtonEvent) ?? false;
}
[Service(Exported = true, Enabled = true)]
[IntentFilter(new[] { ServiceInterface })]
public class MediaBrowserService : MediaBrowserServiceCompat, AudioManager.IOnAudioFocusChangeListener
{
private MediaSessionCompat mediaSession;
private MediaSessionCompatCallback mediaSessionCallback;
private void CreateMediaSessionCallback()
{
mediaSessionCallback = new MediaSessionCompatCallback()
{
MediaButtonEvent = OnMediaButtonEvent
};
}
private void SetupMediaSession()
{
CreateMediaSessionCallback();
var stateBuilder = new PlaybackStateCompat.Builder().SetActions(PlaybackStateCompat.ActionPlay | PlaybackStateCompat.ActionPlayPause);
mediaSession = new MediaSessionCompat(this, nameof(MediaBrowserService));
mediaSession.SetFlags(MediaSessionCompat.FlagHandlesMediaButtons | MediaSessionCompat.FlagHandlesTransportControls);
mediaSession.SetPlaybackState(stateBuilder.Build());
mediaSession.SetCallback(mediaSessionCallback);
mediaSession.Active = true;
SessionToken = mediaSession.SessionToken;
}
private void BuildNotification() { [...] }
public override void OnCreate()
{
base.OnCreate();
SetupMediaSession();
StartForeground(135, BuildNotification());
ContextCompat.StartForegroundService(ApplicationContext, new Intent(ApplicationContext, Java.Lang.Class.FromType(typeof(MediaBrowserService))));
}
public override void OnDestroy()
{
base.OnDestroy();
if (mediaSession != null)
{
mediaSession.Active = false;
mediaSession.SetCallback(null);
mediaSession.Release();
mediaSession.Dispose();
mediaSession = null;
}
if (mediaSessionCallback != null)
{
mediaSessionCallback.Dispose();
mediaSessionCallback = null;
}
StopForeground(true);
StopSelf();
}
}

Trouble establishing WebSocket4Net connection with Xamarin.Forms Android project

We've recently reorganized our socket connections to have them use more shared code. I currently have the iOS project able to connect to the web socket and respond to events but I haven't been successful yet with the android project. It will try to connect and eventually hit the disconnect event with data stating "transport error". I'm wondering if anyone with more experience with sockets knows if there are any key differences between an iOS connection and an android connection? I'll post some of my code below and try to cut out the chunks I don't think are related. Thank you!!
This is my shared class
public bool InitAndConnect()
{
//Create a socket
sock = DependencyService.Get<IDabSocket>(DependencyFetchTarget.NewInstance);
//Get the URL to use
ContentConfig config = ContentConfig.Instance;
string uri;
if (GlobalResources.TestMode)
{
uri = config.app_settings.stage_journal_link;
}
else
{
uri = config.app_settings.prod_journal_link;
}
//Create list of events to monitor (basic connection events are already monitored)
List<String> events = new List<String>();
events.Add("room_error");
events.Add("join_error");
events.Add("auth_error");
events.Add("update");
//Register for notifications from the socket
sock.DabSocketEvent += Sock_DabSocketEvent;
//Init the socket
sock.Init(uri, events);
//Connect the socket
sock.Connect();
return true;
}
public bool JoinRoom(DateTime date)
{
//Joins a room for a specific date
var room = date.ToString("yyyy-MM-dd");
var token = AuthenticationAPI.CurrentToken;
var data = new DabJournalObject(room, token);
var json = JObject.FromObject(data);
//Send data to the socket
sock.Emit("join", json);
//Store the date we're using
currentDate = date;
return true;
}
//IsConnected returns a bool indicating whether the socket is currently connected.
//This is a bindable property
public bool IsConnected
{
get
{
return sock == null ? false : sock.IsConnected;
}
}
//Opposite of IsConnected used for binding reasons.
public bool IsDisconnected
{
get
{
return sock == null ? true : !sock.IsConnected;
}
}
private void Sock_DabSocketEvent(object sender, DabSocketEventHandler e)
{
//An event has been fired by the socket. Respond accordingly
//Log the event to the debugger
Debug.WriteLine($"{e.eventName} was fired with {e.data}");
//Take action on the event
switch (e.eventName.ToLower())
{
case "disconnected": //Socket disconnected
Sock_Disconnected(e.data);
break;
case "connected": //Socket connected
Sock_Connected(e.data);
break;
case "reconnecting": //Socket reconnecting
sock.Connect();
//do nothing for now
break;
case "reconnected": //Socket reconnected
Sock_Connected(e.data);
break;
case "room_error": //Error with a room
Sock_ErrorOccured(e.eventName, e.data);
break;
case "join_error": //Error joining
Sock_ErrorOccured(e.eventName, e.data);
break;
case "auth_error": //Error with authentication
Sock_ErrorOccured(e.eventName, e.data);
break;
case "update": //update happened externally
Sock_ExternalUpdateOccured(e.eventName, e.data);
break;
default:
break;
}
}
private void Sock_Disconnected(string data)
{
//The socket got disconnected.
//Notify UI
OnPropertyChanged("IsConnected");
OnPropertyChanged("IsDisconnected");
}
private void Sock_Connected(object data)
{
//The socket has connected or reconnected. Take appropriate action
//Notify UI
OnPropertyChanged("IsConnected");
OnPropertyChanged("IsDisconnected");
}
/* Events to handle Binding */
public virtual void OnPropertyChanged(string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null)
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
this is my android class
public bool IsConnected
{
get
{
return isConnected;
}
}
public void Connect(string token)
{
//Make sure the socket is initialized
if (!isInitialized) throw new Exception("You must initialize the socket before using it");
sock.Connect();
}
public void Init(string Uri, List<String> events)
{
//Initialize the socket
try
{
sock = IO.Socket(Uri);
isInitialized = true;
//Set up standard events
sock.On("connect", data => OnConnect(data));
sock.On("disconnect", data => OnDisconnect(data));
sock.On("reconnect", data => OnReconnect(data));
sock.On("reconnecting", data => OnReconnecting(data));
//Set up custom events requested by the caller
foreach (string s in events)
{
sock.On(s, data => OnEvent(s, data));
}
}
catch (Exception ex)
{
isInitialized = false;
isConnected = false;
}
}
private object OnEvent(string s, object data)
{
//A requested event has fired - notify the calling app so it can handle it.
//Notify the listener
DabSocketEvent?.Invoke(this, new DabSocketEventHandler(s, data.ToString()));
return data;
}
private object OnConnect(object data)
{
//Socket has connected (1st time)
isConnected = true;
//Notify the listener
DabSocketEvent?.Invoke(this, new DabSocketEventHandler("connected", data.ToString()));
//Return
return data;
}
private object OnDisconnect(object data)
{
//Socket has disconnected
isConnected = false;
//Notify the listener
DabSocketEvent?.Invoke(this, new DabSocketEventHandler("disconnected", data.ToString()));
//Return
return data;
}
public void Disconnect()
{
if (IsConnected)
{
sock.Disconnect();
}
}
public void Connect()
{
sock.Connect();
}
public void Emit(string Command, object Data)
{
sock.Emit(Command, Data);
}
public void Open()
{
sock.Open();
}
My iOS class looks really similar to the droid class.. besides the Open().. Not sure what is hanging up on the android side.

My SocketIoClientDotNet nuget package versions didn't match between my iOS and android projects. Once I updated my android package to match the version in the iOS project everything worked great.

Always Check if there is Internet Connection Xamarin forms

I am doing a xamarin forms app, i want to check every second if there is a internet connection, if the connection is lost, the program should go to diferent page.
I am using the plugin "Xam.Plugin.Connectivity" , but doesnt do what i want.
Is possible to do what i want?

Edit: this can be easily done with the new Xamarin Essentials Connectivity plugin, just follow the instructions there :D
Create a method in your App.cs (or App.xaml.cs) like this:
private async void CheckConnection()
{
if(!CrossConnectivity.Current.IsConnected)
await Navigation.PushAsync(new YourPageWhenThereIsNoConnection());
else
return;
}
And use it on your main app method like this:
public App()
{
InitializeComponent();
var seconds = TimeSpan.FromSeconds(1);
Xamarin.Forms.Device.StartTimer(seconds,
() =>
{
CheckConnection();
});
}

Never used, but this is a documentation about the plugin you are using
Detecting Connectivity Changes
Often you may need to notify your user or respond based on network changes. You can do this by subscribing several different events.
Changes in Connectivity
When any network connectivity is gained, changed, or loss you can register for an event to fire:
/// <summary>
/// Event handler when connection changes
/// </summary>
event ConnectivityChangedEventHandler ConnectivityChanged;
You will get a ConnectivityChangeEventArgs with the status if you are connected or not:
public class ConnectivityChangedEventArgs : EventArgs
{
public bool IsConnected { get; set; }
}
public delegate void ConnectivityChangedEventHandler(object sender, ConnectivityChangedEventArgs e);
CrossConnectivity.Current.ConnectivityChanged += async (sender, args) =>
{
Debug.WriteLine($"Connectivity changed to {args.IsConnected}");
};
Changes in Connectivity Type
When any network connectivity type is changed this event is triggered. Often it also is accompanied by a ConnectivityChanged event.
/// <summary>
/// Event handler when connection type changes
/// </summary>
event ConnectivityTypeChangedEventHandler ConnectivityTypeChanged;
When this occurs an event will be triggered with EventArgs that have the most recent information:
public class ConnectivityTypeChangedEventArgs : EventArgs
{
public bool IsConnected { get; set; }
public IEnumerable<ConnectionType> ConnectionTypes { get; set; }
}
public delegate void ConnectivityTypeChangedEventHandler(object sender, ConnectivityTypeChangedEventArgs e);
Example:
CrossConnectivity.Current.ConnectivityTypeChanged += async (sender, args) =>
{
Debug.WriteLine($"Connectivity changed to {args.IsConnected}");
foreach(var t in args.ConnectionTypes)
Debug.WriteLine($"Connection Type {t}");
};

Problems with receiving UDP messages in Metro-Apps

I'm currently working on a project and one of the featured devices is a Windows Tablet. To "connect" it to other devices (like some Raspberry Pi) in the project environment UDP is used to send messages. The Windows Tablet is intended to be some controlling device with soem touch functionality. Therefore I'm writing an App (and the intention of the App is not to put it into the Windows Store). The UDP part in this work is quite painful because I had to do much research since I started with no experience in App programming. More painful than the programming is, that I practically finished the work only to start over again because the App didn't receive UDP anymore.
Here's my code (I removed elements not relevant to the actual problem). I apologize for the bad coding....
App.xaml.cs:
sealed partial class App : Application
{
NetworkInterface ni = new NetworkInterface();
public App()
{
this.InitializeComponent();
this.Suspending += OnSuspending;
ni.MessageReceived += OnMessageReceived;
ni.Connect(new HostName("127.0.0.1"), "5556");
}
private void OnMessageReceived(object sender, MessageReceivedEventArgs e)
{
Debug.WriteLine("Processing");
Debug.WriteLine(e.Message.Data);
}
public static new App Current
{
get { return Application.Current as App; }
}
private DatagramSocket _socket;
protected override void OnLaunched(LaunchActivatedEventArgs e)
{
Update_Timer();
}
DispatcherTimer timer = new DispatcherTimer();
private void Update_Timer()
{
timer.Start();
timer.Interval = new TimeSpan(0,0,0,0,500);
timer.Tick += alive;
}
private void alive(object sender, object e)
{
if (start == 0) {
Debug.WriteLine("App-Startup");
ni.SendMessage("Startup...");
start++;
}
else
{
Debug.WriteLine("App-Alive");
ni.SendMessage("alive");
start++;
}
}
}
This part of code is to send and receive Messages in the backgrond in the whole App.
And a NetworkInterface class:
class NetworkInterface
{
private DatagramSocket _socket;
public bool IsConnected { get; set; }
public NetworkInterface()
{
IsConnected = false;
_socket = new DatagramSocket();
_socket.MessageReceived += OnSocketMessageReceived;
}
public async void Connect(HostName remoteHostName, string remoteServiceNameOrPort)
{
if (IsConnected != true)
{
await _socket.BindServiceNameAsync("5321");
await _socket.ConnectAsync(remoteHostName, remoteServiceNameOrPort);
}
IsConnected = true;
}
public void alive(object sender, object e)
{
Debug.WriteLine("alive");
}
public event EventHandler<MessageReceivedEventArgs> MessageReceived;
private void OnSocketMessageReceived(DatagramSocket sender, DatagramSocketMessageReceivedEventArgs args)
{
var reader = args.GetDataReader();
var count = reader.UnconsumedBufferLength;
var data = reader.ReadString(count);
Debug.WriteLine(args);
if (MessageReceived != null)
{
var ea = new MessageReceivedEventArgs();
ea.Message = new Message() { Data = data };
ea.RemoteHostName = args.RemoteAddress;
ea.RemotePort = args.RemotePort;
MessageReceived(this, ea);
}
}
DataWriter _writer = null;
public async void SendMessage(string message)
{
if (_writer == null)
{
var stream = _socket.OutputStream;
_writer = new DataWriter(stream);
}
_writer.WriteString(message);
await _writer.StoreAsync();
}
}
The main problems are:
If I dont send something before receiving, I won't be able top get an message.
If I send before I have random Faults at this line:
var reader = args.GetDataReader();
If nothing fails, I'm not able to receive messages from a local Python script (which works) but I can send messages from a local program which the App receives.
Does anyone know how I can fix these problems?
Thanks in advance!

Where to listen for broadcast action with MVVMCross

Making my Bluetooth application I need access to some broadcast actions on the Android side of my code.
All this is run in my Core, so I have a ViewModel that will call through my interface
public interface IConnectionService
{
//Properties
string IntentName { get; }
//Events
event EventHandler<SearchConnectionItemEventArgs> SearchItemFoundEvent;
//Methods
void RunIntent();
void SearchConnection();
void Connect(string macAddress);
}
RunIntent prompts the user to turn on Bluetooth (Could be another technology) and I would then like to have an event trigger when Bluetooth state is changed
Android.Bluetooth.BluetoothAdapter.ActionStateChanged
And also when I search for new devices I need
Android.Bluetooth.BluetoothDevice.ActionFound
But I cant put the [Android.Runtime.Register("ACTION_FOUND")] and [Android.Runtime.Register("ACTION_STATE_CHANGED")] on my class, this only works if I try to put it on my View, but if I do that I need logic in my view?
Is it possible to put it in the core somehow?
My class implementing my interface
using System;
using Android.Bluetooth;
using Android.Content;
using Cirrious.MvvmCross.Android.Platform.Tasks;
using Test.Core.Interfaces;
using Test.Core.Models;
namespace Test.Core.Android
{
public class AndroidBluetooth : MvxAndroidTask, IConnectionService
{
#region Private Fields
private readonly BluetoothAdapter _bluetoothAdapter;
#endregion
#region Public Fields
#endregion
#region Properties
public string IntentName { get { return "Turn on Bluetooth"; }}
#endregion
#region Constructor
public AndroidBluetooth()
{
_bluetoothAdapter = BluetoothAdapter.DefaultAdapter;
}
#endregion
#region Events
public event EventHandler<SearchConnectionItemEventArgs> SearchItemFoundEvent;
private void ItemFound(SearchConnectionItemEventArgs e)
{
if(SearchItemFoundEvent != null)
{
SearchItemFoundEvent(this, e);
}
}
#endregion
#region Methods
public void RunIntent()
{
if (_bluetoothAdapter == null)
{
//No bluetooth support on phone
}
else if(!_bluetoothAdapter.IsEnabled)
{
var intent = new Intent(BluetoothAdapter.ActionRequestEnable);
StartActivity(intent);
}
}
public void SearchConnection()
{
if (_bluetoothAdapter == null)
{
//No bluetooth support on phone
}
else if (!_bluetoothAdapter.IsEnabled)
{
//Bluetooth not turned on
RunIntent();
}
else
{
FindBondedDevices();
}
}
private void FindBondedDevices()
{
var pairedDevices = _bluetoothAdapter.BondedDevices;
if (pairedDevices.Count <= 0) return;
foreach (var item in pairedDevices)
{
ItemFound(new SearchConnectionItemEventArgs {Name = item.Name, MacAddress = item.Address});
}
}
private void FindNewDevices()
{
if (_bluetoothAdapter == null)
{
}
else if (!_bluetoothAdapter.IsEnabled)
{
}
else
{
_bluetoothAdapter.StartDiscovery();
//Bind event for new devices
}
}
public void Connect(string macAddress)
{
}
#endregion
}
}

Disclaimer: I'm not familiar with this part of Android - I've never used the Bluetooth stack.
From your description it sounds like you already know the answer - these Attributes need to go on methods within the Activity/View.
Of course, once they've been added to the Activity/View then it is easy to route these method calls through to the ViewModel - just use the ViewModel property within the View.
It's probably easier to try to get this part of your working as a standalone sample first - and then work out how to make it cross-platform and/or mvvm.