Is UDP Sockets working on Win8, Win8.1 ?

Question

Hi

I need to use UDP sockets to connect to udp server. As server I have used a desktop VLC player with streaming video through UDP on 127.0.0.1:1234 . I have used next code for Win8, Win8.1 to receive data from VLC :

#include <ppl.h>
#include <ppltasks.h>

#include <future>

using namespace Windows::Networking;
using namespace Windows::Networking::Sockets;

DatagramSocket ^udp;

// helper to not mess with writing code for CompletedHandler's
static bool PerformSync(Windows::Foundation::IAsyncAction ^op)
{
	std::promise<bool> prom;
	auto fut = prom.get_future();

	op->Completed = ref new Windows::Foundation::AsyncActionCompletedHandler(
		[&](Windows::Foundation::IAsyncAction ^op, Windows::Foundation::AsyncStatus status)
	{
		if (status == Windows::Foundation::AsyncStatus::Completed)
		{
			prom.set_value(true);
		}
		else
		{
			prom.set_value(false);
		}
	});

	auto result = fut.get();

	return result;
}



void Class1::DoTest()
{
	HostName ^hostName = ref new HostName("localhost");
	this->udp = ref new DatagramSocket();

	udp->MessageReceived += ref new Windows::Foundation::TypedEventHandler<Windows::Networking::Sockets::DatagramSocket ^, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs ^>(this, &Class1::OnMessageReceived);
        
        // also tried BindEndpointAsync, same result
	auto op = udp->ConnectAsync(hostName, "1234");

	auto res = PerformSync(op);
}


void Class1::OnMessageReceived(Windows::Networking::Sockets::DatagramSocket ^sender, Windows::Networking::Sockets::DatagramSocketMessageReceivedEventArgs ^args)
{
        // breakpoint on this line are never hit
	int stop = 234;
}

Also I have tried next code on WP8.1 emulator (on WP8.0 emulator it not works), wich works perfectly:

#include <winsock2.h>
#include <Ws2tcpip.h>

// code inside any C++ method on wp8.1 :

        WSADATA wsaData;
	auto wVersionRequested = MAKEWORD(2, 2);

	auto err = WSAStartup(wVersionRequested, &wsaData);

	const int DefaultBufLen = 1024 * 4;
	char recvbuf[DefaultBufLen];
	SOCKET connectSocket = INVALID_SOCKET;
	sockaddr_in clientService;
	int iResult;

	memset(&clientService, 0, sizeof(clientService));

	clientService.sin_addr.S_un.S_un_b.s_b1 = 127;
	clientService.sin_addr.S_un.S_un_b.s_b2 = 0;
	clientService.sin_addr.S_un.S_un_b.s_b3 = 0;
	clientService.sin_addr.S_un.S_un_b.s_b4 = 1;
	
	clientService.sin_family = AF_INET;
	clientService.sin_port = htons(1234);

	connectSocket = socket(AF_INET, SOCK_DGRAM, 0);
	iResult = bind(connectSocket, (SOCKADDR*) &clientService, sizeof(clientService));

	if (iResult == SOCKET_ERROR)
	{
		int stop = 234;
	}

	iResult = recv(connectSocket, recvbuf, DefaultBufLen, 0);

	WSACleanup();

But for some reason winsock2 available only on WP8, WP8.1 .

So is there any way to get UDP sockets to work properly on Win8, Win8.1 or it is possible only on WP8, WP8.1 ?

Answer 1

Hi Alexander - UDP networking is supported in the DatagramSocket class:

http://msdn.microsoft.com/en-us/library/windows/apps/windows.networking.sockets.datagramsocket.aspx

Are you not able to use that class?

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

Answer 2

Sorry for posting not full question :) .

The code inside 1st code block have OnMessageReceived() method and it's never gets called but recv() function inside 2nd code block returns readed bytes from socket. Maybe I missed something in 1st code block ?