Protected Sub lkbScarica_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lkbScarica.Click
       If (DownloadFile()) Then
            'salvo da qualche parte che ha finito...
        End If
    End Sub


   Protected Function DownloadFile() As Boolean
        Dim blOk As Boolean = True
        Try
            HttpContext.Current.Response.ClearContent()
            HttpContext.Current.Response.ClearHeaders()
            HttpContext.Current.Response.AddHeader("Content-Disposition", "inline; filename=" + sNomeFileZip)
            HttpContext.Current.Response.ContentType = "application/zip"
            HttpContext.Current.Response.WriteFile(sNomeFileFullPathZip)
            HttpContext.Current.Response.End()
        Catch exTread As System.Threading.ThreadAbortException
            blOk = True
        Catch ex As Exception
            blOk = False
        End Try

        Return blOk

    End Function