只支持下面几种格式,好像没有xls和pdf对应的dll。没有例子!关注一下!
mimefilt.dll Filters Multipurpose Internet Mail Extension (MIME) files.
nlhtml.dll Filters HTML 3.0 or earlier files.
offfilt.dll Filters Microsoft Office files: Microsoft Word, Microsoft Excel, and Microsoft PowerPoint®.
query.dll Filters plain text files (default filter) and binary files (null filter).