using System;
namespace DocConvert
{
 class DoctoRtf
 {
 static void Main()
 {
  //创建一个word的实例
  Word.application newApp = new Word.Application();
  // 指定源文件和目标文件
  object Source="c:\\abc\\Source.doc";
  object Target="c:\\abc\\Target.rtf";
  object Unknown =Type.Missing;
  // 打开要转换的Word文件
  newApp.Documents.Open(ref Source,ref Unknown,
  ref Unknown,ref Unknown,ref Unknown,
  ref Unknown,ref Unknown,ref Unknown,
  ref Unknown,ref Unknown,ref Unknown,
  ref Unknown );
  // 指定文档的类型
  object format = Word.WdSaveFormat.wdFormatRTF;
  //改变文档类型
  newApp.ActiveDocument.SaveAs(ref Target,ref format,
  ref Unknown,ref Unknown,ref Unknown,
  ref Unknown,ref Unknown,ref Unknown,
  ref Unknown,ref Unknown,ref Unknown);
  //关闭word实例
  newApp.Quit(ref Unknown,ref Unknown,ref Unknown);
 }
 }
}