Visual Basic

Dim oAttachment As New GetAttach
 Try
     Me.Page.Response.Clear()
     Me.Page.Response.ClearContent()
     Me.Page.Response.ClearHeaders()
     Response.ContentType = ""
     Response.BinaryWrite(oAttachment.GetAttach(<The Id of your stored file>))
     Response.AddHeader("content-disposition", "attachment; filename=" + oAttachment.ATTACH_NAME + "." + oAttachment.EXTENSION)
     Me.Page.Response.End()
 Catch ex As Exception
     throw ex
 End Try

Public Function GetAttach(ByVal MyParameter As Integer)
     Dim docFileReader As SqlDataReader

     Try

         Dim Myadapter As New SqlDataAdapter

         Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
             Using command As New SqlCommand("GetAttachment", connection)
                 command.CommandType = CommandType.StoredProcedure
                 command.Parameters.Add(New SqlParameter("@MY_SP_PARAMETER", MyParameter))
                 connection.Open()
                 docFileReader = command.ExecuteReader
                 docFileReader.Read()
                 EXTENSION = docFileReader.Item("EXTENSION").ToString
                 ATTACH_NAME = docFileReader.Item("ATTACH_NAME").ToString
                 WEIGHT = docFileReader.Item("WEIGHT").ToString
                 Dim FileData(docFileReader.GetBytes(0, 0, Nothing, 0, Integer.MaxValue) - 1) As Byte
                 docFileReader.GetBytes(0, 0, FileData, 0, FileData.Length)
                 docFileReader.Close()

                 Return FileData

             End Using
         End Using

     Catch ex As Exception
         If IsNothing(docFileReader) = False Then
             docFileReader.Close()
         End If
         Throw ex
     End Try

 End Function