Convert word documents .doc to .pdf in batch.

Program.cs

// Install Nuget Package "NetOffice.Word"
using NetOffice.WordApi;
using System;
using System.IO;

namespace word2pdf
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            if (args == null || args.Length == 0)
            {
                PrintUsage();
                return;
            }

            var directoryPath = Path.GetFullPath(args[0]);

            if (!Directory.Exists(directoryPath))
            {
                PrintUsage();
                return;
            }

            Console.WriteLine("Converting word documents in {0}", directoryPath);

            using (var word = new Application())
            {
                foreach (var documentPath in Directory.GetFiles(directoryPath, "*.doc"))
                {
                    var fileName = Path.GetFileNameWithoutExtension(documentPath);
                    Console.WriteLine("Converting {0}", fileName);
                    var pdfPath = Path.Combine(directoryPath, fileName + ".pdf");
                    var document = word.Documents.Open(documentPath);
                    document.ExportAsFixedFormat(pdfPath, NetOffice.WordApi.Enums.WdExportFormat.wdExportFormatPDF);
                    document.Close(false);
                    Console.WriteLine("document {0}.pdf created", fileName);
                }

                word.Quit();
            }

            Console.WriteLine("Done");
        }

        private static void PrintUsage()
        {
            Console.WriteLine("Please specify a valid Path");
            Console.WriteLine("Example:");
            Console.WriteLine("    word2pdf C:\\docs");
            Console.WriteLine();
        }
    }
}