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

  • Today's agile organizations pose operations teams with a tremendous challenge: to deploy new releases to production immediately after development and testing is completed. To ensure that applications are deployed successfully, an automatic and transparent process is required. We refer to this process as Zero Touch Deployment™. This white paper reviews two approaches to Zero Touch Deployment--a script-based solution and a release automation platform. The article discusses how each can solve the key …

  • On-demand Event Event Date: December 18, 2014 The Internet of Things (IoT) incorporates physical devices into business processes using predictive analytics. While it relies heavily on existing Internet technologies, it differs by including physical devices, specialized protocols, physical analytics, and a unique partner network. To capture the real business value of IoT, the industry must move beyond customized projects to general patterns and platforms. Check out this webcast and join industry experts as …

Most Popular Programming Stories

More for Developers

RSS Feeds