My software handles multiple operations on files, and I have now finished writing the related functions, using the
You can use the UNC path (which starts with
\\) directly in your paths. However, you must account for the credentials for this connection, which can be the tricky part.
There are several approaches:
If the remote system is on the same domain or there is a trust relationship between the domains, and the user your program is running as has suitable access, it will "just work".
You can shell out and execute the
net use command (through the Windows
net.exe program) to make a connection with a specific username and password. Be aware that connection is usable by any program running in the user's session, not just your application. Use the
/DELETE command to remove the connection when you are done. The typical syntax is:
net use \\computername\sharename password /USER:domain\username.
You can P/Invoke
WNetAddConnection2 to accomplish the same thing as
net use without shelling out to
net.exe. By passing NULL as
lpLocalName, no drive letter is assigned, but the username and password will apply to subsequent accesses made through the UNC path. The
WNetCancelConnection2 function can be used to disconnect.
You can P/Invoke
LogonUser with the
LOGON32_LOGON_NEW_CREDENTIALS flag followed by an impersonation to add additional remote credentials to your thread. Unlike #2 and #3, the effects on the user's entire session will be a little more limited. (In practice, this is rarely done in favor of the well-known
The following is a sample of how to call
WNetAddConnection2 from VB.NET.
Private Sub Test() Dim nr As New NETRESOURCE nr.dwType = RESOURCETYPE_DISK nr.lpRemoteName = "\\computer\share" If WNetAddConnection2(nr, "password", "user", 0) <> NO_ERROR Then Throw New Exception("WNetAddConnection2 failed.") End If 'Code to use connection here.' If WNetCancelConnection2("\\computer\share", 0, True) <> NO_ERROR Then Throw New Exception("WNetCancelConnection2 failed.") End If End Sub <StructLayout(LayoutKind.Sequential)> _ Private Structure NETRESOURCE Public dwScope As UInteger Public dwType As UInteger Public dwDisplayType As UInteger Public dwUsage As UInteger <MarshalAs(UnmanagedType.LPTStr)> _ Public lpLocalName As String <MarshalAs(UnmanagedType.LPTStr)> _ Public lpRemoteName As String <MarshalAs(UnmanagedType.LPTStr)> _ Public lpComment As String <MarshalAs(UnmanagedType.LPTStr)> _ Public lpProvider As String End Structure Private Const NO_ERROR As UInteger = 0 Private Const RESOURCETYPE_DISK As UInteger = 1 <DllImport("mpr.dll", CharSet:=CharSet.Auto)> _ Private Shared Function WNetAddConnection2(ByRef lpNetResource As NETRESOURCE, <[In](), MarshalAs(UnmanagedType.LPTStr)> ByVal lpPassword As String, <[In](), MarshalAs(UnmanagedType.LPTStr)> ByVal lpUserName As String, ByVal dwFlags As UInteger) As UInteger End Function <DllImport("mpr.dll", CharSet:=CharSet.Auto)> _ Private Shared Function WNetCancelConnection2(<[In](), MarshalAs(UnmanagedType.LPTStr)> ByVal lpName As String, ByVal dwFlags As UInteger, <MarshalAs(UnmanagedType.Bool)> ByVal fForce As Boolean) As UInteger End Function