PDFOne .NET
Powerful all-in-one PDF library for .NET

Compatibility

VS 2005/2008/2010/2012/2013

Home » Newsletter » February 2015

AcroForms is an interactive feature of PDF that has been one of the main reasons for its popularity and success. Sometimes, however, you need to get rid of all interactivity from the form fields. This is done to make the form fields read-only with whatever values that had been entered by the end-users who submitted them. This is usually done prior to archiving the PDF documents in a storage system. The process of removing the interactive features from a PDF form is called form flattening.

With PDFOne .NET, form flattening is a simple affair. Load a document and call the FlattenFormFields() method. This method is available for both PDFDocument and PDFPage classes. In this former, the method accepts a page range. In the latter, the method affects form fields in the instant PDF page.

PDF Form Flattening Example

private void button1_Click(object sender, EventArgs e) {
  PDFDocument doc = new PDFDocument("your-license-key");
  doc.Load("forms_doc.pdf");

  doc.FlattenFormFields("1");  // Flattens form fields on page 1
            
  doc.Save("flattened_forms_doc.pdf");
  doc.Close();
}

Here is the input PDF forms document.

And, here is the modified flattened PDF document. It looks the same but the form fields are not interactive anymore.

You can download both documents and see for yourself.