用iTextSharp填充单选按钮组

using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

public class Program
{
    public static void Main(string[] args)
    {
        // 读取现有的PDF文档
        PdfReader reader = new PdfReader("input.pdf");

        // 创建一个新的PDF文档
        using (FileStream fs = new FileStream("output.pdf", FileMode.Create))
        {
            PdfStamper stamper = new PdfStamper(reader, fs);

            // 获取单选按钮组的字段对象
            AcroFields fields = stamper.AcroFields;
            AcroFields.FieldPosition fieldPosition = fields.GetFieldPositions("radioGroup")[0];
            int pageNumber = fieldPosition.page;

            // 设置字段的值
            fields.SetField("radioGroup", "option1");

            // 绘制单选按钮的选中状态
            PdfContentByte contentByte = stamper.GetOverContent(pageNumber);
            RadioCheckField radioField = new RadioCheckField(stamper.Writer, fieldPosition.position, "option1", "Yes");
            radioField.CheckType = RadioCheckField.TYPE_CHECK;
            radioField.Checked = true;
            PdfFormField field = radioField.CheckField;
            contentByte.AddAnnotation(field, pageNumber);

            // 关闭PDF文档
            stamper.Close();
        }

        Console.WriteLine("单选按钮组已填充并保存为output.pdf");
    }
}