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: December 11, 2014 @ 1:00 p.m. ET / 10:00 a.m. PT Market pressures to move more quickly and develop innovative applications are forcing organizations to rethink how they develop and release applications. The combination of public clouds and physical back-end infrastructures are a means to get applications out faster. However, these hybrid solutions complicate DevOps adoption, with application delivery pipelines that span across complex hybrid cloud and non-cloud environments. Check out this …

  • On-demand Event Event Date: October 29, 2014 It's well understood how critical version control is for code. However, its importance to DevOps isn't always recognized. The 2014 DevOps Survey of Practice shows that one of the key predictors of DevOps success is putting all production environment artifacts into version control. In this webcast, Gene Kim discusses these survey findings and shares woeful tales of artifact management gone wrong! Gene also shares examples of how high-performing DevOps …

Most Popular Programming Stories

More for Developers

RSS Feeds