Upload pdf files in ASP.net

protected void upload_Click(object sender, EventArgs e)

    {
        Label2.Visible = true;
        string filePath = FileUpload1.PostedFile.FileName;          // getting the file path of uploaded file
        string filename1 = Path.GetFileName(filePath);               // getting the file name of uploaded file
        string ext = Path.GetExtension(filename1);                      // getting the file extension of uploaded file
        string type = String.Empty;
 
 if (!FileUpload1.HasFile)
        {
            Label2.Text = "Please Select File";                          //if file uploader has no file selected
        }
        else
        if (FileUpload1.HasFile)
        {
            try
            {
                                                     
                switch (ext)                                         // this switch code validate the files which allow to upload only PDF  file 
                {
                    case ".pdf": 
                        type = "application/pdf"; 
                        break;                 
                 
                }
 
                if (type != String.Empty)
                { 
                   connection();
                    Stream fs = FileUpload1.PostedFile.InputStream;
                    BinaryReader br = new BinaryReader(fs);                                 //reads the   binary files
                    Byte[] bytes = br.ReadBytes((Int32)fs.Length);                           //counting the file length into bytes
                    query = "insert into PDFFiles (Name,type,data)" + " values (@Name, @type, @Data)";   //insert query
                    com = new SqlCommand(query, con);
                    com.Parameters.Add("@Name", SqlDbType.VarChar).Value = filename1;
                    com.Parameters.Add("@type", SqlDbType.VarChar).Value = type;
                    com.Parameters.Add("@Data", SqlDbType.Binary).Value = bytes;
                    com.ExecuteNonQuery();
                    Label2.ForeColor = System.Drawing.Color.Green;
                    Label2.Text = "File Uploaded Successfully"; 
                }
                else
                {
                    Label2.ForeColor = System.Drawing.Color.Red; 
                    Label2.Text = "Select Only PDF Files  ";                              // if file is other than speified extension 
                }
            }
            catch (Exception ex)
            {
                Label2.Text = "Error: " + ex.Message.ToString(); 
            } 
        }
    }


//Add the following code in the view file button click to View uploaded PDF files in GridView


protected void Button2_Click(object sender, EventArgs e)
    {
        connection();
        query = "Select *from PDFFiles";
        SqlDataAdapter da = new SqlDataAdapter(query, con);
        DataSet ds = new DataSet();
        da.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
        con.Close();

    }

//Add the following code to the Gridview selected index changed event to download the files:

    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
        {
             connection();
            SqlCommand com =new SqlCommand("select Name,type,data from  PDFFiles where id=@id", con);
            com.Parameters.AddWithValue("id", GridView1.SelectedRow.Cells[1].Text);
            SqlDataReader dr = com.ExecuteReader();

 
            if (dr.Read())
            {
                Response.Clear();
                Response.Buffer =true;
                Response.ContentType = dr["type"].ToString();
                Response.AddHeader("content-disposition", "attachment;filename=" + dr["Name"].ToString());     // to open file prompt Box open or Save file         
                Response.Charset = "";
                Response.Cache.SetCacheability(HttpCacheability.NoCache);
                Response.BinaryWrite((byte[])dr["data"]);
                Response.End();
            }

}