PosPrinter.FromIdAsync() returns null in WinUI3 app, no pairing dialog shown

[1888games]

Describe the bug

Using XF/UWP, we are successfully using the Windows.Devices.PointOfService.PosPrinting API to connect to network receipt printers.

The PosPrinter.FromIdAsync() call will popup a dialog for the user to confirm they wish to pair with the printer. From there we claim the printer, enable, and send it a print job.

Using MAUI/WinUI3, the same code with the same 'pointOfService' capability set in the manifest returns null almost instantly. No dialog is shown. I know the printer is available because I retrieved the ID using:

DeviceInformation.FindAllAsync(PosPrinter.GetDeviceSelector(PosConnectionTypes.IP));

...and I can of course run the UWP version side by side and successfully get the PosPrinter handle using the same ID once I have confirmed using the pairing dialog.

The same happens on a vanilla WinUI3 app without using MAUI.

Steps to reproduce the bug

1. Ensure a POS printer (such as Epson TM-M30) is connected to the network.
2. Create a blank WinUI3 desktop app.
3. Add PointOfService capability to the manifest.
4. Add this method to MainWindow.xaml.cs and call PosPrinting() in the myButton_Click listener.

async void PosPrinting()
        {

            DeviceInformationCollection deviceCollection = await DeviceInformation.FindAllAsync(PosPrinter.GetDeviceSelector(PosConnectionTypes.IP));

            if (deviceCollection.Count > 0)
            {
                DeviceInformation deviceInfo = deviceCollection[0];

                PosPrinter p = await PosPrinter.FromIdAsync(deviceInfo.Id);

                if (p != null)
                {
                    Debug.WriteLine(p.DeviceId);
                }

            }
        }

p will be null.

Expected behavior

Successfully retrieve a PosPrinter object using PosPrinter.FromIdAsync(deviceInfo.Id). If first attempt to connect to the PosPrinter, first show a dialog for the user to confirm pairing.

Screenshots

NuGet package version

No response

Windows app type

• UWP
• Win32

Device form factor

Desktop

Windows version

Windows 11 (21H2): Build 22000

Additional context

Microsoft.WindowsAppSDK versions is

1.1.3
1.2.2.220902.1.-preview1

[1888games]

This is what happens using the same code on UWP:

[ssparach]

/external

[microsoft-github-policy-service]

Hi @@1888games, thank you for your contribution! This issue appears to be external to the WindowsAppSDK. To help route it appropriately, please submit your feedback via the Feedback Hub by pressing [Windows] + [F], and include detailed information and diagnostics. We appreciate your help in improving the platform!