Getting a file’s short name (8.3 format) in .NET

Using short file names is not something that should be needed anymore, probably violates most “best practices“ and will likely be deprecated in the future. I assume this is why Microsoft did not provide an easy method for finding a file’s short name with the .NET Framework. Unfortunately, while writing an interface to an older, poorly written application, I needed to supply the short name for some files. The code below outlines how to do this. Usage should be self-explanatory. The System.Runtime.InteropServices and System.Text classes will need to be imported.

Public Class Interop    <DllImport(“kernel32.dll”, SetLastError:=True, CharSet:=CharSet.Auto)> _
    Public Shared Function GetShortPathName(ByVal longPath As String, <MarshalAs(UnmanagedType.LPTStr)> ByVal ShortPath As StringBuilder, <MarshalAs(UnmanagedType.U4)> ByVal bufferSize As Integer) As Integer
    End Function

End Class

Private Function GetShortName(ByVal strPath As String, ByVal blnIncludePath As Boolean) As String
    Dim sb As StringBuilder = New StringBuilder(1024)
    Dim retVal As Integer = Interop.GetShortPathName(strPath, sb, 1024)
    GetShortName = sb.ToString
    If Not blnIncludePath Then
       GetShortName = Mid(GetShortName, InStrRev(GetShortName, “\”) + 1)
    End If
End Function