Dim Filepath As String = Label7.Text
        Dim fileStream As New FileStream(Filepath, FileMode.Open)
        Dim fileSize As Long = fileStream.Length
        Dim inta As Integer = CInt(fileSize)
        Dim OutPutFileName As String = " linkbutton1.text" 
        Response.ContentType = "application/octet-stream"
        Response.AddHeader("Content-Disposition", "attachment; filename=" & HttpUtility.UrlEncode(OutPutFileName, System.Text.Encoding.UTF8))
        Response.AddHeader("Content-Length", fileSize.ToString())
        Dim fileBuffer(inta) As Byte
        fileStream.Read(fileBuffer, 0, inta)
        fileStream.Close()
        Response.BinaryWrite(fileBuffer)
        Response.End()linkbutton1.text为下载的文件文件名。。但是下载下来的文件却没有后缀,无法打开为什么??