How to Work with the Facades API in .NET

The Facades API provides high-level wrappers for common PDF tasks. This guide covers form filling, file merging, and content editing.

Prerequisites

Requirement	Detail
Runtime	.NET 8.0 or later
Package	`dotnet add package Aspose.Pdf.Foss`

Fill a form field

The Form facade opens an input PDF, fills fields by name, and writes the result to a separate output file. This avoids working with the low-level Document object when all you need is simple field population.

using var form = new Form("input.pdf", "output.pdf");
form.FillField("FirstName", "Alice");
form.Save();

Merge two PDFs

PdfFileEditor concatenates multiple PDF files into one output document. Pass the source file paths and a destination path to produce a single merged result.

var editor = new PdfFileEditor();
editor.Concatenate("file1.pdf", "file2.pdf", "merged.pdf");

Extract a page range

The same PdfFileEditor class can extract a contiguous range of pages into a new file. Specify the start page, end page, and output path.

var editor = new PdfFileEditor();
editor.Extract("source.pdf", 2, 5, "pages2to5.pdf");

Key Classes

Class	Purpose
`Form`	Read and write form field values
`PdfFileEditor`	Merge, split, extract pages
`PdfContentEditor`	Edit page content
`PdfFileSignature`	Sign and verify documents
`PdfFileStamp`	Add stamps to pages
`PdfConverter`	Render pages to images

How to Work with the Facades API in .NET