// 转化类

// pathinfo 选择文件夹位置

// file 对象名

public void TranWordDocToDocx(string pathinfo, string file)

        {

            Microsoft.Office.Interop.Word.Application word = new Microsoft.Office.Interop.Word.Application();

            Microsoft.Office.Interop.Word.Document doc = new Microsoft.Office.Interop.Word.Document();

            object oMissing = System.Reflection.Missing.Value;

            Object ConfirmConversions = false;

            Object ReadOnly = false;

            Object AddToRecentFiles = false;

            Object PasswordDocument = "";

            Object PasswordTemplate = System.Type.Missing;

            Object Revert = System.Type.Missing;

            Object WritePasswordDocument = System.Type.Missing;

            Object WritePasswordTemplate = System.Type.Missing;

            Object Format = System.Type.Missing;

            Object Encoding = System.Type.Missing;

            Object Visible = System.Type.Missing;

            Object OpenAndRepair = System.Type.Missing;

            Object DocumentDirection = System.Type.Missing;

            Object NoEncodingDialog = System.Type.Missing;

            Object XMLTransform = System.Type.Missing;

            Object fileName = pathinfo + "\\" + file;

            doc = word.Documents.Open(ref fileName, ref ConfirmConversions,

            ref ReadOnly, ref AddToRecentFiles, ref PasswordDocument, ref PasswordTemplate,

            ref Revert, ref WritePasswordDocument, ref WritePasswordTemplate, ref Format,

            ref Encoding, ref Visible, ref OpenAndRepair, ref DocumentDirection,

            ref NoEncodingDialog, ref XMLTransform);

            DirectoryInfo directory = new DirectoryInfo(pathinfo + "\\docx");

            if (!directory.Exists)//不存在

            {

                directory.Create();

            }

            object path = pathinfo + "\\docx\\" + file.Substring(0, file.Length - 4);

            //以下参数控制转换类型，网上查到的全是错误的，是doc类型

            object format = Microsoft.Office.Interop.Word.WdSaveFormat.wdFormatXMLDocument;

            doc.SaveAs(ref path, ref format, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing);

            doc.Close(ref oMissing, ref oMissing, ref oMissing);

            word.Quit(ref oMissing, ref oMissing, ref oMissing);

        }

//调用实例

private void button1_Click(object sender, EventArgs e)

        {

            if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)

            {

                this.txtDocPaths.Text = folderBrowserDialog1.SelectedPath;

            }

            DirectoryInfo folder = new DirectoryInfo(this.txtDocPaths.Text);

            foreach (FileInfo file in folder.GetFiles("*.doc"))

            {

                if (file.ToString().IndexOf("$") == -1)

                {

                    this.lblMsg.Text = string.Format("当前处理的文件：{0}", file.FullName);

                    this.lblMsg.Refresh();

                    TranWordDocToDocx(this.txtDocPaths.Text, file.ToString());

                }

            }

        }

//using

using Microsoft.CodeAnalysis;

using Microsoft.Office.Interop.Word;

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;