Zeroconf: Unable to get txt records

Question

I've been trying to use Onovotny's Zeroconf package in my 8.1 phone app. It discovers the service that I'm looking for but none of the TXT records come back.

In iOS I'm using NSNetServiceBrowser and for Android, JmDNS. Both give me everything I need, so I know it isn't the service.

This is the code I'm using:

public async Task StartDiscovery()
{
    Action<IZeroconfHost> callback = new Action<IZeroconfHost>((IZeroconfHost host) => 
    {
        Debug.WriteLine(host.Services.Count); 
    });

    IReadOnlyList<IZeroconfHost> results = 
        await ZeroconfResolver.ResolveAsync(SERVICE_TYPE, new TimeSpan(0, 0, 10), 4, 2000, callback);
    Debug.WriteLine(results);
}

When I set a break point in my callback, this is what I see.

I'm not sure if I'm doing something wrong or if the library doesn't handle my situation. Either way, any help would be greatly appreciated.

Note: I posted an issue at the Zeroconf GitHub repo a couple of days ago but haven't received a response.

Answer 1

Instead of using the NuGet package, I pulled the code into my project and set a few breakpoints.

In ZeroconfResolver.cs, when I change Additionals to Answers I get the txt records for my service.

ZeroconfResolver.cs line 249

// Get the matching service records
var serviceRecords = response.Answers
    .Where(r => r.NAME == ptrRec.PTRDNAME)
    .Select(r => r.RECORD)
    .ToList();

Edit: Merging the Additionals and Answers lists is a better way to go.

List<RR> resourceRecords = new List<RR>().Union(response.Answers).Union(response.Additionals).ToList();
// Get the matching service records
var serviceRecords = resourceRecords
    .Where(r => r.NAME == ptrRec.PTRDNAME)
    .Select(r => r.RECORD)
    .ToList();