Imports System
Imports System.IO
Imports System.Security.AccessControl
 
Module FileExample
 
    Sub Main()
        Try
            Dim fileName As String = "test.xml"
 
            Console.WriteLine("Adding access control entry for " & fileName)
 
            ' Add the access control entry to the file.
            AddFileSecurity(fileName, "DomainName\AccountName", _
                FileSystemRights.ReadData, AccessControlType.Allow)
 
            Console.WriteLine("Removing access control entry from " & fileName)
 
            ' Remove the access control entry from the file.
            RemoveFileSecurity(fileName, "DomainName\AccountName", _
                FileSystemRights.ReadData, AccessControlType.Allow)
 
            Console.WriteLine("Done.")
        Catch e As Exception
            Console.WriteLine(e)
        End Try
 
    End Sub
 
 
    ' Adds an ACL entry on the specified file for the specified account.
    Sub AddFileSecurity(ByVal fileName As String, ByVal account As String, _
        ByVal rights As FileSystemRights, ByVal controlType As _
        AccessControlType)
 
        ' Get a FileSecurity object that represents the 
        ' current security settings.
        Dim fSecurity As FileSecurity = File.GetAccessControl(fileName)
 
        ' Add the FileSystemAccessRule to the security settings. 
        Dim accessRule As FileSystemAccessRule = _
            New FileSystemAccessRule(account, rights, controlType)
 
        fSecurity.AddAccessRule(accessRule)
 
        ' Set the new access settings.
        File.SetAccessControl(fileName, fSecurity)
 
    End Sub
 
 
    ' Removes an ACL entry on the specified file for the specified account.
    Sub RemoveFileSecurity(ByVal fileName As String, ByVal account As String, _
        ByVal rights As FileSystemRights, ByVal controlType As _
        AccessControlType)
 
        ' Get a FileSecurity object that represents the 
        ' current security settings.
        Dim fSecurity As FileSecurity = File.GetAccessControl(fileName)
 
        ' Add the FileSystemAccessRule to the security settings. 
        fSecurity.RemoveAccessRule(New FileSystemAccessRule(account, _
            rights, controlType))
 
        ' Set the new access settings.
        File.SetAccessControl(fileName, fSecurity)
 
    End Sub
End Module

Ralf