.Net Maui Can't connect to localhost from Android Emulator

New Contributor

Hi all,


I need to connect to my server app (Elixir/Phoenix) over websockets, and currently have iOS and MacOS builds connecting fine, but I am getting the following error when running the app in the Android emulator:




Fatal|WebSocket.connect|System.Net.Internals.SocketExceptionFactory+ExtendedSocketException (111): Connection refused [::ffff:]:4002




Has anyone come across this before?


I'm using PhoenixSharp to connect to my server app. When I build with it I get the following warning:



: Warning NU1701: Package 'WebSocketSharp 1.0.3-rc11' was restored using '.NETFramework,Version=v4.6.1, .NETFramework,Version=v4.6.2, .NETFramework,Version=v4.7, .NETFramework,Version=v4.7.1, .NETFramework,Version=v4.7.2, .NETFramework,Version=v4.8, .NETFramework,Version=v4.8.1' instead of the project target framework '.NETStandard,Version=v2.0'. This package may not be fully compatible with your project. (NU1701) (Phoenix)



Could this relate to the problem with Android?


Here's the relevant code (which I expected to work on all devices):



using Phoenix;

var socketOptions = new Socket.Options(new JsonMessageSerializer());
var socketAddress = "ws://localhost:4002/socket";
var socketFactory = new WebsocketSharpFactory();
var socket = new Socket(socketAddress, new Dictionary<string, string>(), socketFactory, socketOptions);




Visual Studio 2022 (Mac)

.Net 7.0.200

Android Pixel 5 (Api 33)


I'm happy to provide any additional info that may help.


Many thanks



Edit: The warning mentioned above is not the issue. I've resolved that now. Also, I can connect to my remote server fine from the Android emulator, I just can't get to localhost on my dev machine.

1 Reply

Hi @paulhollyer,

Thanks for posting your issue here.

However this platform is used for how-to discussions and sharing best practices for building any app with .NET.Since your issue is a technical question, welcome to post it in Microsoft Q&A forum, the support team and communities on Microsoft Q&A will help you for any technical questions.
Besides, it will be appreciated if you can share it here once you post this technical question Microsoft Q&A.
Best Regards,
Lan Huang