PDF Export

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.Master" 
         AutoEventWireup="true" CodeBehind="Default.aspx.cs" 
         Inherits="OnlyOfficeControl._Default" ValidateRequest="false" %>
<%@ Register Src="~/Controls/OnlyOfficeEditor/OnlyOfficeEditor.ascx" 
             TagPrefix="oo" TagName="Editor" %>

<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
    <link rel="stylesheet" href="<%= ResolveUrl("~/Content/WebEditor.css") %>" />

    <div class="we">
        <section class="we-toolbar">
            <div class="we-toolbar__left">
                <asp:FileUpload ID="fuFile" runat="server" 
                                CssClass="form-control we-input" />
            </div>
            <div class="we-toolbar__right">
                <asp:Button ID="btnUpload" runat="server" 
                            Text="Upload and Open" 
                            CssClass="btn we-btn we-btn-accent" 
                            OnClick="btnUpload_Click" />
            </div>
            <div class="we-toolbar__status">
                <asp:Literal ID="litStatus" runat="server" />
            </div>
        </section>

        <div class="we-layout">
            <main class="we-main">
                <div class="we-surface">
                    <div class="we-surface__head">
                        <div class="we-surface__title">Document</div>
                        <div class="we-surface__meta">OnlyOffice Editor</div>
                    </div>
                    <oo:Editor ID="docEditor" runat="server" 
                               CaptureTriggerId="btnDescargar" />
                </div>
            </main>

            <aside class="we-aside">
                <div class="we-surface we-surface--sticky">
                    <div class="we-surface__head">
                        <div class="we-surface__title">Actions</div>
                        <div class="we-surface__meta">Export Options</div>
                    </div>

                    <div class="we-asideActions">
                        <asp:Button ID="btnDescargar" runat="server" 
                                    Text="Save and Download as PDF" 
                                    CssClass="btn we-btn we-btn-accent we-btn-block" 
                                    OnClick="btnDescargar_Click" />
                        <div class="we-asideHint">
                            Download the edited document as PDF
                        </div>
                    </div>
                </div>
            </aside>
        </div>
    </div>
</asp:Content>

using System;
using System.IO;
using System.Web.UI;

namespace OnlyOfficeControl
{
    public partial class _Default : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            // Optional: Load a default document
            if (!IsPostBack)
            {
                string sampleFilePath = Server.MapPath("~/doc.docx");
                if (File.Exists(sampleFilePath))
                {
                    byte[] fileBytes = File.ReadAllBytes(sampleFilePath);
                    docEditor.SetDocumentFromBytes(fileBytes, "doc.docx");
                }
            }
        }

        protected void btnUpload_Click(object sender, EventArgs e)
        {
            if (!fuFile.HasFile)
            {
                litStatus.Text = string.Empty;
                return;
            }

            docEditor.SetDocumentFromBytes(fuFile.FileBytes, fuFile.FileName);
            litStatus.Text = string.Empty;
        }

        protected void btnDescargar_Click(object sender, EventArgs e)
        {
            // Convert the edited document to PDF
            byte[] documentBytes = docEditor.ConvertCurrentDocumentToPdfBytes();

            if (documentBytes == null || documentBytes.Length == 0)
            {
                litStatus.Text = "<span class='text-warning'>No document to download.</span>";
                return;
            }

            // Clear the edited document from memory
            docEditor.ClearEditedDocument();

            // Prepare the filename
            var ext = Path.GetExtension(docEditor.DocumentName ?? ".docx");
            var fileName = docEditor.DocumentName ?? ("documento" + ext);

            // Send the PDF to the browser
            Response.Clear();
            Response.ContentType = "application/octet-stream";
            Response.AddHeader("Content-Disposition", 
                "attachment; filename=" + fileName + ".pdf");
            Response.AddHeader("Content-Length", documentBytes.Length.ToString());
            Response.BinaryWrite(documentBytes);
            Response.End();
        }
    }
}