PrintDlgEx invalid argument, while PrintDlg works - c++

Question

Problem: I need to get PrintDlgEx working for my project, but no combination of options or arguments works for me. It gives E_INVALIDARG for any combinations of options, as the ones I copied from Microsoft samples or other online samples.
Replacing PRINTDLGEX with PRINTDLG and PrintDlgEx with PrintDlg (and eliminating the group of options only from PRINTDLGEX) works fine.
Unfortunately I need PrintDlgEx, because I really need the Apply button, to change printers or property sheet without printing, for design and preview.
Please help me find why I can't get the dialog to show.
Code: while I simplified pieces, like what should happen on successful return, or setting DEVMODE and DEVNAMES, I tried this function exactly, with the same result: Invalid Argument.
#include <QDebug>
#include <QWindow>
#include <windows.h>
void showPrintDialog()
{
// Simplifying the setup: real code passes in a QWidget *
QWidget *caller = this;
// Not returning a value or doing any work. I just want the dialog to pop up for now
// Create the standard windows print dialog
PRINTDLGEX printDialog;
memset(&printDialog, 0, sizeof(PRINTDLGEX));
printDialog.lStructSize = sizeof(PRINTDLGEX);
printDialog.Flags = PD_RETURNDC | // Return a printer device context. Without this, HDC may be undefined
PD_USEDEVMODECOPIESANDCOLLATE |
PD_NOSELECTION | // Don't allow selecting individual document pages to print
PD_NOPAGENUMS | // Disables some boxes
PD_NOCURRENTPAGE | // Disables some boxes
PD_NONETWORKBUTTON | // Don't allow networking (but it show "Find printer") so what does this do ?
PD_HIDEPRINTTOFILE; // Don't allow print to file
// Only on PRINTDLGEX
// Theis block copied from https://learn.microsoft.com/en-us/windows/win32/dlgbox/using-common-dialog-boxes?redirectedfrom=MSDN
// I have tried multiple combinations of options, including none, I really don't want any of them
printDialog.nStartPage = START_PAGE_GENERAL;
printDialog.nPageRanges = 1;
printDialog.nMaxPageRanges = 10;
LPPRINTPAGERANGE pageRange = (LPPRINTPAGERANGE) GlobalAlloc(GPTR, 10 * sizeof(PRINTPAGERANGE));
printDialog.lpPageRanges = pageRange;
printDialog.lpPageRanges[0].nFromPage = 1;
printDialog.lpPageRanges[0].nToPage = 1;
printDialog.Flags2 = 0;
printDialog.ExclusionFlags = 0;
printDialog.dwResultAction = 0; // This will tell me if PRINT
// Rest of options are also on PRINTDLG
printDialog.nMinPage = 1;
printDialog.nMaxPage = 10;
// The only options I really need
printDialog.nCopies = 1;
printDialog.hDevMode = Q_NULLPTR; // which will be better once this works
printDialog.hDevNames = Q_NULLPTR; // which will be better once this works
printDialog.hwndOwner = reinterpret_cast<HWND>(caller->windowHandle()->winId());
// Calling...
int result = PrintDlgEx(&printDialog);
qDebug() << (result == E_INVALIDARG ? "Invalid Argument\n" : "Success\n");
// It always is E_INVALIDARG
// Cleanup
if (printDialog.hDevMode)
GlobalFree(printDialog.hDevMode);
if (printDialog.hDevNames)
GlobalFree(printDialog.hDevNames);
if (printDialog.hDC)
DeleteDC(printDialog.hDC);
}
Platform: Windows 10, latest update;
Qt version: 5.12.7 or higher
(since in VM I have 5.15.1)
The fact that I am running in Qt should be irrelevant, since this is all WIN API, beyond the c++ version (11)

Answer 1

I can make your example work if I remove PD_NONETWORKBUTTON flag.
Please note that while it is documented for PRINTDLGA struct, it is NOT listed in PRINTDLGEXA
NOTE: I did get the same error with that flag.