blob download counter in .net

I need to add a download counter to know how many times my BLOB data is read and displayed from the database (to determine traffic). How and where can I add this counter? Many thanks!

I have a dynamically generated list of links such as <a href="page.aspx?DocID=IDhere">Document filename</a> which direct to a display page.

My display page code looks like:

Protected Sub Page_Load

    Dim DocID As Integer = Convert.ToInt32(Request.QueryString("DocID"))
    Dim connStr As String = conn string 开发者_StackOverflow社区here
    Dim SqlCmd1 As String = "SELECT DocID, DocBD, Filename, MIMEType WHERE DocID=@DocID"
    Dim conn As SqlConnection = New SqlConnection(connStr)
    Dim Cmd1 As SqlCommand = New SqlCommand(sqlCmd1, conn)
    With Cmd1.Parameters
        .Add(New SqlParameter("@DocID", DocID)
    End With
        Try
        conn.Open()
        Dim myReader As SqlDataReader = Cmd1.ExecuteReader
        If myReader.Read Then
                Response.ClearContent()
                Response.AddHeader("content-disposition", "inline; filename=" & myReader("Filename"))
                Response.ContentType = myReader("MIMEType").ToString()
                Response.BinaryWrite(myReader("DocBD"))
                Response.End()
        Else
        Label1.Text = "The document you requested doesn't exist in the database. Please contact the document owner"
        End If
        myReader.Close()
   Catch ex As Exception
        Label1.Text = ex.Message()
   Finally
   conn.Close()
   End Try
End Sub

Hopefully this will help you out. It's for uploading, but maybe you can use it as a reference for downloading.

public void ProcessRequest(HttpContext context, string uploadPath)
    {
        string filename = context.Request.QueryString["filename"];
        bool complete = string.IsNullOrEmpty(context.Request.QueryString["Complete"]) ? true : bool.Parse(context.Request.QueryString["Complete"]);
        bool getBytes = string.IsNullOrEmpty(context.Request.QueryString["GetBytes"]) ? false : bool.Parse(context.Request.QueryString["GetBytes"]);
        long startByte = string.IsNullOrEmpty(context.Request.QueryString["StartByte"]) ? 0 : long.Parse(context.Request.QueryString["StartByte"]); ;

        string filePath;
        if (UniqueUserUpload)
        {
            if (context.User.Identity.IsAuthenticated)
            {
                filePath = Path.Combine(uploadPath, string.Format("{0}_{1}", context.User.Identity.Name.Replace("\\",""), filename));
            }
            else
            {
                if (context.Session["fileUploadUser"] == null)
                    context.Session["fileUploadUser"] = Guid.NewGuid();
                filePath = Path.Combine(uploadPath, string.Format("{0}_{1}", context.Session["fileUploadUser"], filename));
            }
        }
        else
            filePath = Path.Combine(uploadPath, filename);            

        if (getBytes)
        {
            FileInfo fi = new FileInfo(filePath);
            if (!fi.Exists)
                context.Response.Write("0");
            else
                context.Response.Write(fi.Length.ToString());

            context.Response.Flush();
            return;
        }
        else
        {

            if (startByte > 0 && File.Exists(filePath))
            {

                using (FileStream fs = File.Open(filePath, FileMode.Append))
                {
                    SaveFile(context.Request.InputStream, fs);
                    fs.Close();
                }
            }
            else
            {
                using (FileStream fs = File.Create(filePath))
                {
                    SaveFile(context.Request.InputStream, fs);
                    fs.Close();
                }
            }
            if (complete)
            {
                if (FileUploadCompleted != null)
                {
                    FileUploadCompletedEventArgs args = new FileUploadCompletedEventArgs(filename, filePath);
                    FileUploadCompleted(this, args);
                }
            }
        }
    }

    private void SaveFile(Stream stream, FileStream fs)
    {
        byte[] buffer = new byte[4096];
        int bytesRead;
        while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) != 0)
        {
            fs.Write(buffer, 0, bytesRead);
        }
    }