Adding text items to an Existing PDF w/ Telerik DocumentProcessing Library - pdf

Question

I want to open an existing PDF document and add different annotations to it. Namely bookmarks and some text
I am using the Telerik Document Processing Library (dpl) v2019.3.1021.40
I am new to dpl , but I believe the RadFlowDocument is the way to go.
I am having troubles creating the RadFlowDocument
FlowProvider.PdfFormatProvider provider = new FlowProvider.PdfFormatProvider();
using (Stream stream = File.OpenRead(sourceFile))
{
--> RadFlowDocument flowDoc = provider.Import(stream);
}
The line indicated w/ the arrow give the error "Import Not Supported"
There is a telerik blog post here
https://www.telerik.com/forums/radflowdocument-to-pdf-error
It seems relevant, but not 100% sure.
It cautions to be sure the providers are mated correctly, I believe they are in my example....
Again, ultimate goal is to open a PDF and add some stuff to it. I think the RadFlowDocument is the right direction. If there is a better solution, Im happy to hear that too.

Answer 1

I figured it out. The DPL is pretty good, but doc is still growing, hope this helps someone out...
This draws from a myriad of articles, I cant begin to cite them all.
There are 2 notions for working w/ PDFs in the DPL.
FixedDocument takes pages. I think this is meant for sewing docs together.
FlowDocument I believe lays things out like an HTML renderer would.
I am using Fixed, mainly b/c I can get that to work.
using System;
using System.IO;
using System.Windows; //nec for Size struct
using System.Diagnostics; //nec for launching the pdf at the end
using Telerik.Windows.Documents.Fixed.Model;
//if you have fixed and flow provider, you have to specify, so I make a shortcut
using FixedProvider = Telerik.Windows.Documents.Fixed.FormatProviders.Pdf;
using Telerik.Windows.Documents.Fixed.Model.Editing;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace DocAggregator
{
[TestClass]
public class UnitTest2
{
[TestMethod]
public void EditNewFIle_SrcAsFixed_TrgAsFixed()
{
String dt = #"C:\USERS\greg\DESKTOP\DPL\";
String sourceFile = dt + "output.pdf";
//Open the sourceDoc so you can add stuff to it
RadFixedDocument sourceDoc;
//a provider parses the actual file into the model.
FixedProvider.PdfFormatProvider fixedProv = new FixedProvider.PdfFormatProvider();
using (Stream stream = File.OpenRead(sourceFile))
{
//'populate' the doc object from the file
//using the FLOW classes, I get "Import Not Supported".
sourceDoc = fixedProv.Import(stream);
}
int pages = sourceDoc.Pages.Count;
int pageCounter = 1;
int xoffset = 150;
int yoffset = 50;
//editor is the thing that lets you add elements into the source doc
//Like the provider, the Editor needs to match the document class (Fixed or Flow)
RadFixedDocumentEditor editor = new RadFixedDocumentEditor(sourceDoc);
foreach (RadFixedPage page in sourceDoc.Pages)
{
FixedContentEditor pEd = new FixedContentEditor(page);
Size ps = page.Size;
pEd.Position.Translate(ps.Width - xoffset, ps.Height - yoffset);
Block block = new Block();
block.HorizontalAlignment = Telerik.Windows.Documents.Fixed.Model.Editing.Flow.HorizontalAlignment.Center;
block.TextProperties.FontSize = 22;
block.InsertText(string.Format("Page {0} of {1} ", pageCounter, pages));
pEd.DrawBlock(block);
pageCounter++;
}
string exportFileName = "addedPageNums.pdf";
if (File.Exists(exportFileName))
{
File.Delete(exportFileName);
}
File.WriteAllBytes(exportFileName, fixedProv.Export(sourceDoc));
//launch the app
Process.Start(exportFileName);
}
}
}