Imports System
Imports System.IO
Imports System.Security.AccessControl
 
Public Class Form1
    Public Projekt As String
    Private Sub ja()
 
        AddFileSecurity(Projekt, ComboBox1.Text, FileSystemRights.ReadData, _
          AccessControlType.Deny)
    End Sub
 
    Private Sub nein()
 
        RemoveFileSecurity(Projekt, ComboBox1.Text, FileSystemRights.ReadData, _
          AccessControlType.Deny)
    End Sub
 
    Private Sub AddFileSecurity(ByVal Projekt As String, ByVal account As _
      String, ByVal rights As FileSystemRights, ByVal controlType As _
      AccessControlType)
        Try
            Dim fSecurity As FileSecurity = File.GetAccessControl(Projekt)
            Dim accessRule As FileSystemAccessRule = New FileSystemAccessRule( _
              account, rights, controlType)
            fSecurity.AddAccessRule(accessRule)
            File.SetAccessControl(Projekt, fSecurity)
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub
 
    Private Sub RemoveFileSecurity(ByVal Projekt As String, ByVal account As _
      String, ByVal rights As FileSystemRights, ByVal controlType As _
      AccessControlType)
        Try
            Dim fSecurity As FileSecurity = File.GetAccessControl(Projekt)
            fSecurity.RemoveAccessRule(New FileSystemAccessRule(account, _
              rights, controlType))
            File.SetAccessControl(Projekt, fSecurity)
        Catch ex As Exception
            MsgBox("Projekt ist nicht mehr vorhanden!")
        End Try
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Projekt = TextBox1.Text
        Call ja()
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        Projekt = TextBox1.Text
        Call nein()
    End Sub
End Class