How to Create, Fill, and Flatten PDF Form Fields in .NET using the Syncfusion® PDF Library

Introduction

A quick start .NET console project that shows how to create, fill, and flatten PDF form fields using the Syncfusion® PDF Library.

System requirement

Framework and SDKs

• .NET SDK (version 5.0 or later)

IDEs

• Visual Studio 2019/ Visual Studio 2022

Code snippet for Create, Fill, and Flatten PDF Form Fields

We will create a new .NET console application, add the Syncfusion® PDF library package, and write the code

static void CreateForm() 
{
    //Create a new PDF document.
    PdfDocument document = new PdfDocument();
    //Add a new page to the PDF document.
    PdfPage page = document.Pages.Add();
    //Set the font.
    PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 16);
    //Draw the text.
    page.Graphics.DrawString("Job Application", font, PdfBrushes.Black, new PointF(250, 0));

    font = new PdfStandardFont(PdfFontFamily.Helvetica, 12);
    page.Graphics.DrawString("Name", font, PdfBrushes.Black, new PointF(10, 20));
    //Create a textbox field and add the properties.
    PdfTextBoxField textBoxField1 = new PdfTextBoxField(page, "Name");
    textBoxField1.Bounds = new RectangleF(10, 40, 200, 20);
    textBoxField1.ToolTip = "Name";
    //Add the form field to the document.
    document.Form.Fields.Add(textBoxField1);

    page.Graphics.DrawString("Email address", font, PdfBrushes.Black, new PointF(10, 80));
    //Create a textbox field and add the properties.
    PdfTextBoxField textBoxField2 = new PdfTextBoxField(page, "Email address");
    textBoxField2.Bounds = new RectangleF(10, 100, 200, 20);
    textBoxField2.ToolTip = "Email address";
    //Add the form field to the document.
    document.Form.Fields.Add(textBoxField2);

    page.Graphics.DrawString("Phone", font, PdfBrushes.Black, new PointF(10, 140));
    //Create a textbox field and add the properties.
    PdfTextBoxField textBoxField3 = new PdfTextBoxField(page, "Phone");
    textBoxField3.Bounds = new RectangleF(10, 160, 200, 20);
    textBoxField3.ToolTip = "Phone";
    //Add the form field to the document.
    document.Form.Fields.Add(textBoxField3);

    page.Graphics.DrawString("Gender", font, PdfBrushes.Black, new PointF(10, 200));
    //Create a Radio button.
    PdfRadioButtonListField employeesRadioList = new PdfRadioButtonListField(page, "Gender");
    //Add the radio button into form.
    document.Form.Fields.Add(employeesRadioList);
    page.Graphics.DrawString("Male", font, PdfBrushes.Black, new PointF(40, 220));
    //Create radio button items.
    PdfRadioButtonListItem radioButtonItem1 = new PdfRadioButtonListItem("Male");
    radioButtonItem1.Bounds = new RectangleF(10, 220, 20, 20);
    page.Graphics.DrawString("Female", font, PdfBrushes.Black, new PointF(140, 220));
    PdfRadioButtonListItem radioButtonItem2 = new PdfRadioButtonListItem("Female");
    radioButtonItem2.Bounds = new RectangleF(110, 220, 20, 20);
    //Add the items to radio button group.
    employeesRadioList.Items.Add(radioButtonItem1);
    employeesRadioList.Items.Add(radioButtonItem2);

    //Create file stream.
    using (FileStream outputFileStream = new FileStream("Output.pdf", FileMode.Create, FileAccess.ReadWrite)) 
    {       
        //Save the PDF document to file stream. 
        document.Save(outputFileStream);
    }
    //Close the document.
    document.Close(true);
}

static void FillForm() 
{
    //Get stream from an existing PDF document. 
    FileStream docStream = new FileStream("Output.pdf", FileMode.Open, FileAccess.Read);
    //Load the existing PDF document.
    PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
    //Load the form from the loaded document.
    PdfLoadedForm form = loadedDocument.Form;
    //Load the form field collections from the form.
    PdfLoadedFormFieldCollection fieldCollection = form.Fields as PdfLoadedFormFieldCollection;
    PdfLoadedField loadedField = null;

    //Get the field using TryGetField Method.
    if (fieldCollection.TryGetField("Name", out loadedField)) {
        (loadedField as PdfLoadedTextBoxField).Text = "Simons";
    }
    if (fieldCollection.TryGetField("Email address", out loadedField)) {
        (loadedField as PdfLoadedTextBoxField).Text = "simonsbistro@outlook.com";
    }
    if (fieldCollection.TryGetField("Phone", out loadedField)) {
        (loadedField as PdfLoadedTextBoxField).Text = "31 12 34 56";
    }
    if (fieldCollection.TryGetField("Gender", out loadedField)) {
        (loadedField as PdfLoadedRadioButtonListField).SelectedIndex = 0;
    }
    //Flatten the whole form.
    form.Flatten = true;
    
    //Create file stream.
    using (FileStream outputFileStream = new FileStream("FilledPDF.pdf", FileMode.Create, FileAccess.ReadWrite)) {
        //Save the PDF document to file stream. 
        loadedDocument.Save(outputFileStream);
    }
    //Close the document.
    loadedDocument.Close(true);
}

Output Image

CreateFormPDF

FilledPDF

How to run the examples

• Download this project to a location in your disk.
• Open the solution file using Visual Studio.
• Rebuild the solution to install the required NuGet package.
• Run the application.

Resources

• Product page: Syncfusion® PDF Framework
• Documentation page: Syncfusion® .NET PDF library
• Online demo: Syncfusion® .NET PDF library - Online demos
• Blog: Syncfusion® .NET PDF library - Blog
• Knowledge Base: Syncfusion® .NET PDF library - Knowledge Base
• EBooks: Syncfusion® .NET PDF library - EBooks
• FAQ: Syncfusion® .NET PDF library - FAQ

Support and feedback

• For any other queries, reach our Syncfusion® support team or post the queries through the community forums.
• Request new feature through Syncfusion® feedback portal.

License

This is a commercial product and requires a paid license for possession or use. Syncfusion’s licensed software, including this component, is subject to the terms and conditions of Syncfusion's EULA. You can purchase a licnense here or start a free 30-day trial here.

About Syncfusion®

Founded in 2001 and headquartered in Research Triangle Park, N.C., Syncfusion® has more than 26,000+ customers and more than 1 million users, including large financial institutions, Fortune 500 companies, and global IT consultancies.

Today, we provide 1600+ components and frameworks for web (Blazor, ASP.NET Core, ASP.NET MVC, ASP.NET WebForms, JavaScript, Angular, React, Vue, and Flutter), mobile (Xamarin, Flutter, UWP, and JavaScript), and desktop development (WinForms, WPF, WinUI(Preview), Flutter and UWP). We provide ready-to-deploy enterprise software for dashboards, reports, data integration, and big data processing. Many customers have saved millions in licensing fees by deploying our software.