'Contextmenu dynamisch erzeugen
Protected Sub cmscol_opening(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles cmsCol.Opening
        Dim i As Integer = 1
        Do Until i = dgv.Columns.Count
 
            If dgv.Columns(i).Visible = True Then
                cmsCol.Items.Add(dgv.Columns(i).Name)
 
 
            End If
            i = i + 1
        Loop
    End Sub
    'DropdownItems beim schließen löschen
    Private Sub cmsCol_Closing(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.ToolStripDropDownClosingEventArgs) Handles _
      cmsCol.Closing
        MISelCol.DropDownItems.Clear()
    End Sub