Does discovery work at all?

[Salazander]

I am currently trying to create wrappers around multiple mDNS-SD implementations. Using DeviceInformation.CreateWatcher seems to be the UWP-native way of discovering devices. So I tried adapting DnssdParticipant for my purposes.

The issue I am facing: After calling StartListeningAsync, the watcher's Added and Updated-event never get triggered.

I modified _aqsQueryString in order to discover all services in our network, not only the service type that was defined for the sample game. I went as far as only specifying:

private string _aqsQueryString = $"System.Devices.AepService.ProtocolId:={PROTOCOL_GUID}";

where

private const string PROTOCOL_GUID = "{4526e8c1-8aac-4153-9b16-55e86ada0e54}";

I tried adding additional quotation marks around the GUID, but to no avail.

Either I am doing something completely wrong or something is broken with the functionality surrounding mDNS-SD. Can anybody confirm that the corresponding UWP-APIs should be working fine with following OS/IDE versions?
Win 10 1803 17134.765
VS2019 16.04

[derekpiasecki]

I can't seem to get DeviceWatcher to work with DNS-SD either:

string aqsFilter = "System.Devices.AepService.ProtocolId:=\"{4526e8c1-8aac-4153-9b16-55e86ada0e54}\" AND System.Devices.Dnssd.ServiceName:=\"_ndi._tcp\"";

string[] requestedProperties = new string[] {
    "System.Devices.Dnssd.HostName",
    "System.Devices.Dnssd.ServiceName",
    "System.Devices.Dnssd.TextAttributes",
    "System.Devices.IpAddress",
};

DeviceWatcher deviceWatcher = DeviceInformation.CreateWatcher(aqsFilter, requestedProperties, DeviceInformationKind.AssociationEndpointService);
...

However, the Win32 DnsServiceBrowse() API works on the same machine (tested on both 19041 and a recent canary build of Windows 11).