如何打印所有的pdf文件，图片和文档文件从文件夹在.net C#的打印预览？

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

namespace PrintPreviewExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string folderPath = "文件夹路径";

            string[] files = Directory.GetFiles(folderPath);

            foreach (string file in files)
            {
                string extension = Path.GetExtension(file);

                if (IsPdfFile(extension))
                {
                    PreviewPdf(file);
                }
                else if (IsImageFile(extension) || IsDocumentFile(extension))
                {
                    PreviewFile(file);
                }
            }

            Console.ReadLine();
        }

        static bool IsPdfFile(string extension)
        {
            return extension.Equals(".pdf", StringComparison.OrdinalIgnoreCase);
        }

        static bool IsImageFile(string extension)
        {
            string[] imageExtensions = { ".jpg", ".jpeg", ".png", ".gif" };
            return Array.Exists(imageExtensions, e => e.Equals(extension, StringComparison.OrdinalIgnoreCase));
        }

        static bool IsDocumentFile(string extension)
        {
            string[] documentExtensions = { ".doc", ".docx", ".txt" };
            return Array.Exists(documentExtensions, e => e.Equals(extension, StringComparison.OrdinalIgnoreCase));
        }

        static void PreviewPdf(string filePath)
        {
            using (PdfReader reader = new PdfReader(filePath))
            {
                int pageCount = reader.NumberOfPages;

                for (int i = 1; i <= pageCount; i++)
                {
                    using (PdfDocument document = new PdfDocument())
                    {
                        document.AddPage(reader.GetPageN(i));

                        using (MemoryStream ms = new MemoryStream())
                        {
                            PdfWriter writer = PdfWriter.GetInstance(document, ms);
                            document.Open();

                            // 打印预览操作，可以根据需要自定义

                            document.Close();
                        }
                    }
                }
            }
        }

        static void PreviewFile(string filePath)
        {
            Process.Start(filePath);
        }
    }
}