使用PInvokes可以使用的 IFilter的接口（在Windows上）。对于许多常见的文件类型的IFilter的安装与Windows（您可以使用这个。一>工具，你可以只问的IFilter从文件返回你的文字有几套例如code的（的这里就是这样一个例子）。

Using PInvokes you can use the IFilter interface (on Windows). The IFilters for many common file types are installed with Windows (you can browse them using this tool. You can just ask the IFilter to return you the text from the file. There are several sets of example code (here is one such example).