Mounting Network Drives

Environment: Windows 95, Visual C++ 6

We had a need for users to not tie up file sharing licenses all day when not needed.

Since they only needed the network drive mounted for one app, I embedded routines in the app to automatically check for the drive non-existence, prompt for password, and mount the drive.

I created the password screen exactly the same as the one NT shows for mounting drives. Then I created the wrapped class for it, called CDriveMountDlg.

In the application Doc.cpp, I check for a folder on the network drive. If it exists, fine, do nothing. Otherwise, call the CDriveMountDlg, and get the password.

I begin a loop of drive letters, attempting to mount the network drive for each one until successful, or I run out of letters. I save the letter for unmounting later.

#include <io.h> ...
BOOL CMounterDoc::OnNewDocument()
{
 if (!CDocument::OnNewDocument())
  return FALSE;

 // Check if \\APPS1\data is mounted
 // -1 means failed
 if( (_access( "\\\\apps1\\data\\parcel", 0 )) == -1 ) 
 {
  CDriveMountDlg  dlg;
  int response = dlg.DoModal();
  if (response == IDCANCEL)
   return FALSE;

  NETRESOURCE resource;
  resource.dwType = RESOURCETYPE_ANY;
  resource.lpRemoteName = "\\\\apps1\\data";
  resource.lpProvider = NULL;

  int nDrive = 4;
  CString sDrive;

  sDrive.Format("%c:", nDrive + 'A');
  resource.lpLocalName = sDrive.GetBuffer(2);

  DWORD result = WNetAddConnection2(&resource, 
   (LPCSTR)dlg.m_sPassword, NULL, 0);

  while ((result != 0) && (nDrive < 25))
  {
   nDrive++;
   sDrive.Format("%c:", nDrive + 'A');
   result = WNetAddConnection2(&resource, 
    (LPCSTR)dlg.m_sPassword, NULL, 0);
  }

  if (result != 0)
  {
   AfxMessageBox("Unable to find a free drive. Aborting.");
   return FALSE;
  }

  m_sDrive = sDrive;
  m_bMountFlag = TRUE;
 }
}

When the application exits, it calls OnCloseDocument



void CMounterDoc::OnCloseDocument() 
{
      if (m_bMountFlag)
      {
         DWORD result = WNetCancelConnection2(m_sDrive, 
		  0, TRUE);

         if (result != NO_ERROR)
         {
         // Error handling here
         }
      }
   CDocument::OnCloseDocument();
}

Finally, add the file mpr.lib to the project.

WNetAddConnection2 is also supposed to handle empty drive letter strings, creating an invisible connection. This works, although I was unable to disconnect later. Any solutions to this problem would be appreciated.

Downloads

Download demo project - 18 Kb


Comments

  • There are no comments yet. Be the first to comment!

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: July 8, 2015 @ 2:00 p.m. ET / 11:00 a.m. PT With business driving the increasing adoption of agile methodologies such as Continuous Integration and Continuous Deployment, the need for agile database tooling has become even more important. In many companies, the database development lifecycle has become the bottleneck in an otherwise agile delivery process. As such, database professionals are under increasing pressure to shorten delivery timelines even further, only increasing the stakes …

  • Thanks to wide spread cloud hosting and innovations small businesses can meet and exceed the legacy systems of goliath corporations. Explore the freedom to work how you want, with a phone system that will adapt to your evolving needs and actually save you lots of expense—read Get an Enterprise Phone System without High Cost and Complexity. The article clearly illustrates: The only hardware you'll need is phone equipment for advanced voice and fax. How to join all your employees, mobile devices, …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date