Why does QPrinterInfo::availablePrinters return empty list on PC with printers?

Sprezzatura

Both QPrinterInfo::availablePrinters() and QPrinterInfo::availablePrinterNames() return an empty list on Windows PCs that nevertheless show printers when displayed in the Control Panel ➔ Devices & Printers.

The printers are not connected to the computer. I would at least expect Qt to display the "Microsoft Print to PDF". This is also failing on PCs with WiFi printer connections.

Any suggestions on how to get a Printer dialog to display, that is populated with the same list of printers as a native app?

Sprezzatura

The problem was caused by not knowing that I needed to install the following in my app folder:

..\printsupport\windowsprintersupport.dll

Answered here: https://forum.qt.io/topic/39319/solved-qprinterinfo-availableprinters-don-t-list-available-printers

https://forum.qt.io/post/197518