Iterate and modify form fields in code

Updated on Feb 19, 2026

Product Version	Product	Author
2020.1.218	RadPdfProcessing	Dimitar Karamfilov

Description

You have a document that has many form fields and you want to populate them with data in the code.

Solution

You can import the document and iterate all fields. This will allow you to set their value.

csharp

    var provider = new PdfFormatProvider();

    var document = provider.Import(File.ReadAllBytes("form_doc.pdf"));

    foreach (RadFixedPage page in document.Pages)
    {
        
        foreach (Annotation annotation in page.Annotations)
        {
            if (annotation.Type == AnnotationType.Widget)
            {
                Widget widget = (Widget)annotation;
                var field = widget.Field as TextBoxField;
                if (field != null)
                {
                    if (field.Name == "Name")
                    {
                        field.Value = "John Doe";
                    }
                }
            }
        }
    }

    File.WriteAllBytes("result.pdf", provider.Export(document));