WTL Installed Printers List

• Download demo executable - 7 Kb
• Download demo project - 10 Kb

Introduction

Want to fetch an array of installed printers for use in your WTL apps? Easy - just use this class.

First, include the header:

#include "installedprinters.h"

Next, simply create a CInstalledPrinters object and the array will be populated automatically. This class is derived from CSimpleArray<CString>, so you can, for example, fill a listbox using the following code:

CListBox listbox = GetDlgItem(IDC_LIST1);
// Get the list of installed printers
CInstalledPrinters list;
// Fill listbox
for (int i = 0; i < list.GetSize(); i++)
    listbox.AddString(list[i]);

It's as easy as that, The class will use the Win32 EnumPrinters API call, using PRINTER_INFO_5 structures - which is probably the fastest way to enumerate printers (no attempt is made to actually open the printer, as this can be slow if you have network printers installed).

CInstalledPrinters

#pragma once

#include <atlmisc.h>

class CInstalledPrinters : public CSimpleArray<CString>
{
public:
    CInstalledPrinters(void)
    {
        GetPrinters();
    }

    void GetPrinters(void)
    {        
        DWORD dwSize = 0;
        DWORD dwPrinters = 0;
        // Enumerate all installed printers
        if (!::EnumPrinters(PRINTER_ENUM_LOCAL|PRINTER_ENUM_CONNECTIONS, 
               NULL, 5, NULL, 0, &dwSize, &dwPrinters))
        {
            // Check for ERROR_INSUFFICIENT_BUFFER
            // If something else, then quit
            if (::GetLastError() != ERROR_INSUFFICIENT_BUFFER)
                return;
            // Fall through
        }
        // Allocate some buffer memory
        LPBYTE pBuffer = new BYTE [dwSize];
        if (pBuffer == NULL)
            return;
        // Fill the buffer
        // Again, this depends on the O/S
        if (!::EnumPrinters(PRINTER_ENUM_LOCAL|PRINTER_ENUM_CONNECTIONS,
              NULL, 5, pBuffer, dwSize, &dwSize, &dwPrinters))
        {
            // Error - unlikely though
            // as first call to EnumPrinters
            // succeeded!
            return;
        }
        // Do we have any printers?
        if (dwPrinters == 0)
            return;
        // Cast to PRINTER_INFO_2
        PRINTER_INFO_5* pInfo = (PRINTER_INFO_5*)pBuffer;
        // Loop adding the printers to the list
        for (DWORD i = 0; i < dwPrinters; i++, pInfo++)
            Add(CString(pInfo->pPrinterName));
        delete [] pBuffer;
    }
};