Visual Studio

DataGridViewComboBoxColumn accountsComboboxColumn = (DataGridViewComboBoxColumn)TransDataGridView.Columns["Account"];
accountsComboboxColumn.DisplayMember = "xaccountname";
accountsComboboxColumn.ValueMember = "xaccountid";
accountsComboboxColumn.DataSource = dt_Accounts;

TransDataGridView.DataSource = dt_Trans;

Dim sqlcom As New SqlCommand("select bookcontent,bookname from books where  bookn=" & Page.RouteData.Values("bookn").ToString & "", conn)
        Dim da As New SqlDataAdapter(sqlcom)
        Dim ds As New DataTable
        da.Fill(ds)
        Dim filename As String = ds.Rows(0)("bookcontent").ToString
        Dim fff As String = ds.Rows(0)("bookname").ToString
        Dim fileInfo As FileInfo = New FileInfo(filename)
        If fileInfo.Exists Then
            Response.Clear()
            Response.Buffer = True
            Response.Charset = ""
            Response.Cache.SetCacheability(HttpCacheability.NoCache)
            Response.ContentType = "Application/pdf"
            Response.ContentType = "application/ms-word"
            Response.AddHeader("Content-Disposition", "inline; filename=""" & ds.Rows(0)("bookname").ToString & ".pdf" & """")
            Response.AddHeader("Content-Length", fileInfo.Length.ToString())
            Response.TransmitFile(filename)
             Response.Flush()
            HttpContext.Current.ApplicationInstance.CompleteRequest()

Dim Client As New WebClient
Dim weburl As String= ....here is some procedure to get url 
Client.DownloadFileAsync(New Uri(weburl), @"c:\myfile.pdf")