pinvoke.net: Edit: mpr.WNetGetConnection

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Summary: You can use this to get the UNC-Path (Format: "\\Computer\Path\To\Somewhere\") of a Network drive

!!!!C# Signature:
    [DllImport("mpr.dll", CharSet=CharSet.Auto, SetLastError=true)]
    public static extern int WNetGetConnection([MarshalAs(UnmanagedType.LPTStr)] string localName, [MarshalAs(UnmanagedType.LPTStr)] StringBuilder remoteName, ref int length);
!!!!VB Signature:

''' <summary>
    ''' Use to get UNC Path of a Mapped Drive
    ''' </summary>
    ''' <param name="localName"></param>
    ''' <param name="remoteName"></param>
    ''' <param name="length"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    <DllImport("mpr.dll")> _
    Shared Function WNetGetConnection(<MarshalAs(UnmanagedType.LPTStr)> _
                                      ByVal localName As String, ByVal remoteName As System.Text.StringBuilder, _
                                      ByRef length As Integer) As Integer
    End Function

!!!!Alternative VB Signature:
    Declare Function WNetGetConnection Lib "mpr.dll" Alias "WNetGetConnectionA" (ByVal localName As String, ByVal remoteName As System.Text.StringBuilder, ByRef length As Integer) As Integer
!!!!User-Defined Types:
None.

!!!!Notes:
localName is the local name for the network resource (drive or printer)
remoteName is a string builder used to return the network name for the resource
length is the current capacity of the StringBuilder

If the call fails because the StringBuilder is not large enough, the call will return a value of 234, and the Length parameter will contain the required size.

!!!!Tips & Tricks:
Please add some!

!!!!Sample Code:
// This sample code assumes you currently have a drive mapped to p:
// Find out what remote device a local mapping is to
int rc=0;
// Size for the buffer we will use
int bsize=200;
// Create a new stringbuilder, pre-sized as above
StringBuilder rname = new StringBuilder(bsize);
// Call the function
rc = WNetGetConnection("p:", rname, ref bsize);

!!!!Sample Code for Visal Basic 2005 Express Edition:
(Without any Error-Handling)

Declare Function WNetGetConnection Lib "mpr.dll" Alias "WNetGetConnectionA" (ByVal localName As String, _
	ByVal remoteName As System.Text.StringBuilder, ByRef length As Integer) As Integer

Private Function strToUnc(ByVal path As String)
	        Dim length As Integer = 255
	        Dim UNC As New System.Text.StringBuilder(length)
	        WNetGetConnection(Microsoft.VisualBasic.Left(path, 2), UNC, length)
        	Return UNC.ToString
	End Function

'to get the UNC-Path of a network-drive use something like:
	Private Sub Test()
		Dim dr As String = "J:\"
		MsgBox("The UNC-Path of drive " & dr & " is: " & strToUnc(dr))
	End Sub

!!!!Sample Code for VB.NET with error handling:
    
 Declare Function WNetGetConnection Lib "mpr.dll" Alias "WNetGetConnectionA" _
                                      (ByVal localName As String, _
                                      ByVal remoteName As System.Text.StringBuilder, _
                                      ByRef length As Integer) As Integer

Private Sub DisplayUncPath(ByVal aLocalPath As String)

Dim theDriveName As String = aLocalPath.Substring(0, aLocalPath.IndexOf(":") + 1)
        If theDriveName <> "" Then
            Dim theDriveInfo As New DriveInfo(theDriveName)
            If theDriveInfo.DriveType = DriveType.Network Then
                Dim uncPathBuf As New StringBuilder(259)
                Dim err As Integer = WNetGetConnection(theDriveName, uncPathBuf, uncPathBuf.Capacity)
                If err = 0 Then
                    Dim pathname As String = uncPathBuf.ToString()
                    MessageBox.Show(aLocalPath.Replace(theDriveName, pathname))
                Else
                    MessageBox.Show("Failed with error :" & err)
                End If
            Else
                MessageBox.Show(theDriveName & " is not a network mapped path.")
            End If
      End If
 End Sub

!!!!Alternative Managed API:
Do you know one?  Please contribute it!

Documentation: http://msdn.microsoft.com/en-us/library/aa385453(VS.85).aspx