C#编程读取文档Doc，Docx，Pdf的内容

Doc文档：Microsoft Word 14.0 Object Library (GAC对象，调用前需要安装word。安装的word版本不同，COM的版本号也会不同)
Docx文档：Microsoft Word 14.0 Object Library (GAC对象，调用前需要安装word。安装的word版本不同，COM的版本号也会不同)
Pdf文档：PDFBox

/*
     作者：GhostBear
 *   博客地址：Http://blog.csdn.net/ghostbear
 */
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Text.RegularExpressions;
using org.pdfbox.pdmodel;
using org.pdfbox.util;
using Microsoft.Office.Interop.Word;
namespace TestPdfReader
{
    class Program
    {
        static void Main(string[] args)
        {
            //PDF
            PDDocument doc = PDDocument.load(@"C:\resume.pdf");
            PDFTextStripper pdfStripper = new PDFTextStripper();
            string text = pdfStripper.getText(doc);
            string result = text.Replace('\t', ' ').Replace('\n', ' ').Replace('\r', ' ').Replace(" ", "");
            Console.WriteLine(result);
            //Doc,Docx
            object docPath = @"C:\resume.doc";
            object docxPath = @"C:\resume.docx";
            object missing=System.Reflection.Missing.Value;
            object readOnly=true;
            Application wordApp;
            wordApp = new Application();
            Document wordDoc = wordApp.Documents.Open(ref docPath,
                                                  ref missing,
                                                  ref readOnly,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing,
                                                  ref missing);
            string text2 = FilterString(wordDoc.Content.Text);
            wordDoc.Close(ref missing, ref missing, ref missing);
            wordApp.Quit(ref missing, ref missing, ref missing);
            Console.WriteLine(text2);
            Console.Read();
            
        }
        private static string FilterString(string input)
        {
            return Regex.Replace(input, @"(\a|\t|\n|\s+)", "");
           
        }
    }
}