Debug Assertion Failed caused by CreateDC() function

Question

I have a problem with Debug Assertion Failed (picture) Debug Assertion Failed This problem occur when I push "Print" button on dialog box a second time. (on first time work well) Dialog Box: Dialog Box

After debugging code I guess it is caused when I create DC second time. But I can explain why, because ealier I delete DC by DeleteDC() function. Below I put snippets of code when I initialize DC and delete DC.

    BOOL Druk::StartPrint()
{
    //Configuration();
    hDC.CreateDC(DriverName, DeviceName, OutputName, NULL);
    StartDoc(hDC, NULL);
    //StartPage(hDC);
    return TRUE;
}

BOOL Druk::ZakonczDruk()

{
    EndDoc(hDC);
    //EndPage(hDC);
    DeleteDC(hDC);
    return TRUE;
}

Answer 1

It looks like you are using MFC's CDC class, evidenced by

hDC.CreateDC(DriverName, DeviceName, OutputName, NULL);

For symmetry sake, delete it also by that class' method: CDC::DeleteDC

hDC.DeleteDC();