For HTML2PDF and XML2PDF solution check our PDFDoc Scout ActiveX library instead

using System;
using System.Collections.Generic;
using System.Text;
using Bytescout.PDF;
using System.Diagnostics;

namespace HelloWorld
{
class Program
{
static void Main(string[] args)
{
// Create main PDF Doc Engine
PDFDocEngine engine = new PDFDocEngine("", "");

// Add new document
Document document = engine.AddDocument();

// Append new page to the document
Page page = document.AddPage(PageSizeType.A3, PageOrientationType.LandScape);

// Create new drawing
Drawing drawing = page.AddDrawing();

// Add standard font
uint font = document.AddFontStandard(StandardFontType.TimesRoman, FontEncodingType.WinAnsi);

// Set font size
double fontSize = 30;

// Set Active Font
drawing.SetActiveFont(font, fontSize, false, false);

// Set text position
double textX = 500.0f;
double textY = 280.0f;

// Draw Text
drawing.PlaceText(textX, textY, 0, "RadioButtons");

// Set font size
fontSize = 15;

// Set Active Font
drawing.SetActiveFont(font, fontSize, false, false);

// Create new bounding rectangle
Rectangle rect = new Rectangle();

// Set position and size
rect.Left = 500;
rect.Bottom = 500;
rect.Top = 520;
rect.Right = 530;

// Create new radio button
RadioButtonControl radioButton1 = new RadioButtonControl(page, rect, "RadioButton1", "RadioButtonGroup1", true);

// Set caption
radioButton1.Caption = "RadioButton1";

// Set style
radioButton1.SetCheckboxStyle(CheckBoxMarkStyleType.Circle, CheckBoxStyleType.CircleBox);

// Draw text
drawing.PlaceText(535.0f, 330.0f, 0, "RadioButton1");

// Set position and size
rect.Left = 500;
rect.Bottom = 450;
rect.Top = 470;
rect.Right = 530;

// Create new radio button
RadioButtonControl radioButton2 = new RadioButtonControl(page, rect, "RadioButton2", "RadioButtonGroup1", false);

// Set caption
radioButton2.Caption = "RadioButton2";

// Set style
radioButton2.SetCheckboxStyle(CheckBoxMarkStyleType.Circle, CheckBoxStyleType.CircleBox);

// Draw text
drawing.PlaceText(535.0f, 380.0f, 0, "RadioButton2");

// Closing drawing on the page
drawing.Close();

// Save document
document.Save("RadioButton.pdf");

// open generated PDF document in default PDF viewer installed in Windows
Process.Start("RadioButton.pdf");
}
}
}

Download example source code: bytescoutpdf_radiobutton.zip (10 KB)

For HTML2PDF and XML2PDF solution check our PDFDoc Scout ActiveX library instead