Migrating PDF Workflows to Spire.PDF for .NET: Best Practices and Code Samples

Top 10 Spire.PDF for .NET Features Every .NET Developer Should Know

Spire.PDF for .NET is a comprehensive library for creating, reading, editing, and converting PDF documents in .NET applications. Below are the top 10 features that deliver practical value to .NET developers, with short explanations and concise code examples where helpful.

1. Create and Generate PDFs Programmatically

Generate PDFs from scratch with precise control over pages, fonts, and layout.

• Use cases: invoices, reports, printable forms.
• Example (C#):

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var doc = new Spire.Pdf.PdfDocument();
var page = doc.Pages.Add();
page.Canvas.DrawString(“Hello, Spire.PDF!”, new PdfFont(PdfFontFamily.Helvetica, 16f), PdfBrushes.Black, 10, 10);
doc.SaveToFile(“output.pdf”);
doc.Close();

2. Read and Extract Content (Text, Images, Metadata)

Extract text, images, and document metadata for indexing or processing.

• Use cases: search indexing, data extraction from forms.
• Example (C#):

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var doc = new Spire.Pdf.PdfDocument();
doc.LoadFromFile(“input.pdf”);
string text = string.Join(” “, doc.Pages.Select(p => p.ExtractText()));
var info = doc.DocumentInformation;

3. PDF Editing: Modify Pages, Text, and Graphics

Edit existing PDFs—insert/delete pages, replace text, draw shapes, or add watermarks.

• Use cases: dynamic report updates, stamping approvals.
• Example (C#):

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var doc = new Spire.Pdf.PdfDocument();
doc.LoadFromFile(“report.pdf”);
doc.Pages.Insert(1, new Spire.Pdf.PdfPageBase());
doc.Pages[0].Canvas.DrawString(“CONFIDENTIAL”, new PdfFont(PdfFontFamily.Helvetica, 12f), PdfBrushes.Red, 100, 100);
doc.SaveToFile(“edited.pdf”);

4. PDF Conversion to/from Popular Formats

Convert between PDF and Word, Excel, HTML, images, or text.

• Use cases: exporting reports, archiving, generating previews.
• Example (C#) — PDF to Image:

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var doc = new Spire.Pdf.PdfDocument();
doc.LoadFromFile(“input.pdf”);
var image = doc.SaveAsImage(0); // first page as System.Drawing.Image
image.Save(“page1.png”, ImageFormat.Png);

5. Fill and Extract PDF Forms (AcroForms and XFA)

Programmatically fill form fields and extract submitted form data.

• Use cases: automated form filling, processing user submissions.
• Example (C#):

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var doc = new Spire.Pdf.PdfDocument();
doc.LoadFromFile(“form.pdf”);
var field = doc.Form.Fields[“Name”] as Spire.Pdf.Fields.PdfTextBoxField;
field.Text = “Jane Doe”;
doc.SaveToFile(“filledform.pdf”);

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var doc = new Spire.Pdf.PdfDocument();
doc.LoadFromFile(“unsigned.pdf”);
var cert = new X509Certificate2(“cert.pfx”, “password”);
doc.Security.Sign(0, cert, “SignatureReason”, “Location”);
doc.SaveToFile(“signed.pdf”);

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var doc = new Spire.Pdf.PdfDocument();
doc.LoadFromFile(“input.pdf”);
doc.Security.Encrypt(“userPass”, “ownerPass”, Spire.Pdf.Security.PermissionFlags.Print);
doc.SaveToFile(“protected.pdf”);

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var converter = new Spire.Pdf.HtmlConverter.HtmlConverter();
var doc = converter.Convert(“https://example.com”);
doc.SaveToFile(“fromHtml.pdf”);

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var doc = new Spire.Pdf.PdfDocument();
doc.LoadFromFile(“input.pdf”);
doc.SaveToFile(“output_pdfa.pdf”, FileFormat.PDF_A1B);