Unable to Print Longer String to QLn420

Hi Zachary,

So, It's been a while since I've done c++ coding.  Maybe If I share my thought process though, we can figure this out. Your code is sending something to the printer, just not all of it.

First thing to do so you can see what is being output is to go to the generic text driver and in the properties, set the port to FILE:.  Now when you print using this code, it will prompt you for a file location to save the output.  You need to enter a FULL path including file name for it to work.

Second is your Print(LPCTSTR pText) function is actually doing way too much and I was afraid it might be causing the issues.  I cleaned it up as below and got essentially the same output.  This unfortunately didn't solve the problem, but it does make it easier to check that the issue wasn't with the text formatting commands you had it going through.  They are not necessary for printing ZPL through this type of driver.

My thoughts on a few things to check are:

1. Is the close document (EndDoc) coming too soon?  We see this often with slow communication methods where the OS doesn't always verify that a connection may still be writing something before it closes the connection and so the data get's cut off.  I was going to try and introduce a wait or delay at the beginning of the cleanup code to see if it processes more text that way.
2. In your Open() function, are you giving the printer handle a big enough buffer?

bool CPrinter::Print(LPCTSTR pText)
{
  if (!pText) return false;
  if (!mhDC) return false;

  //////////////////// StartDoc
  DOCINFO info = { sizeof(info), 0};
  info.lpszDocName = _T("RFgenOutput");
  if (StartDoc(mhDC, &info) <= 0) {
    _tprintf(_T("StartDoc call failed\n"));
    return false;
  }

  //////////////////// Font setup
  HGDIOBJ hFont=NULL;
  if (mhFont) hFont = SelectObject(mhDC, mhFont);

  SIZE sz={0};
  GetTextExtentPoint32(mhDC, _T("A"), 1, &sz);

  //////////////////// Output to DC
  size_t len = _tcslen(pText);
  TextOut(mhDC, 0, 0, pText, len);

  //////////////////// Cleanup / EndDoc
  Sleep(5000);

  if (hFont) SelectObject(mhDC, hFont);

  bool bEndOK = (EndDoc(mhDC) > 0);

  _DELETEDC(mhDC);
  _DELETEOBJECT(mhFont);

  memset(&mDevMode, 0, sizeof(DEVMODE));
  miWidth = 0;

  if (!bEndOK) {
    _tprintf(_T("EndDoc call failed\n"));
    return false;
  }
  return true;
}