Hololens UDP Receiver: Actually working code does not work in Unity

Hi there,

I got some code for receiving local UDP messages for HoloLens. I tested it with a Visual Studio UWP application and it worked on HoloLens - I am receiving my messages from PC. But the same code actually does not work in Unity although i made sure to check the capability of private networking. I already HAD a working version of the receiver on my HoloLens but I had to recreate my project due to other reasons and like to know what the problem might be.
I am using the SDK 10.0.16299.0 for both applications.

Here is the important code:

Code (CSharp):

1. using UnityEngine;
2. using System.Net;
3. #if !UNITY_EDITOR
4. using System;
5. using System.Threading.Tasks;
6. using System.IO;
7. using Windows.Networking;
8. using Windows.Networking.Sockets;
9. using Windows.Storage.Streams;
10. #endif
11.  
12. public static class Receiver
13. {
14.     static int recvPort = 1337;
15.     static int sendPort = 1338;
16.     public static string log = "";
17.     static DatagramSocket socket;
18.     static DataWriter writer;  
19. #if !UNITY_EDITOR
20.     static DatagramSocket socket;
21.     static DataWriter writer;      
22.  
23.     public static async void Initialize() # gets invoked from outside
24.     {
25.         HostName recvHostname = new HostName("192.168.0.148");
26.         HostName sendHostname = new HostName("192.168.0.112"); //109 is lan, 112 is wlan
27.         socket = new DatagramSocket();
28.         socket.MessageReceived += MessageReceived;
29.         await socket.BindEndpointAsync(recvHostname, recvPort.ToString()); //lokaler Empfangs-Endpunkt und Port
30.         writer = new DataWriter(await
31.             socket.GetOutputStreamAsync(sendHostname, sendPort.ToString())); //erstellt Writer für Output      
32.         Monitor.status += "Initialized."; # this gets invoked
33.         Send(new byte[] { 0x60, 0x70 }); # sending test (fails)
34.     }
35.     public static async void Send(byte[] bytes)
36.     {
37.         writer.WriteBytes(bytes);
38.         await writer.StoreAsync();
39.     }
40.     private static void MessageReceived(DatagramSocket sender, DatagramSocketMessageReceivedEventArgs args)
41.     {
42.         Monitor.status= "msg rcv"; #gets never invoked
43.     }
44. #endif
45. }

The method Initialize() works completely but when I send a message, "MessageReceived" is not invoked.

Kind regards

 

I solved my issue. The mistake was that "IL2CPP" was selected as scripting backend in the player settings. Changing it to ".NET" made the UDP reception work.

 

Dear Dustin, I m having the same problem. But I m using unity 2019 were the scripting backend is only IL2CPP. Do you know if I can do anything else to make it work?