First you need to define your problem. There are lots of ways to "read"
a PDF file, depending on what you really want to do.
If you simply want to display PDF, then the best and easiest approach is
just to use Acrobat Reader. You can use it in the WebBrowser control,
or just launch it standalone.
If you need to examine the structure of the PDF document, then that's
quite a bit harder. For the purpose of converting PDF to text
documents, I have recently been using the "Text Extraction Toolkit" from
PDFLib (
http://www.pdflib.com/products/tet/), and it works quite well.
It has a pretty complicated and user-unfriendly API, which I've wrapped
in a much more convenient and usable managed interface.
(It actually has a managed wrapper with the library, but that wrapper is
_very_ thin and has essentially the same API as the basic C
library…every single option is specified through a relatively arcane
string descriptor. My own wrapper maps regular .NET methods,
properties, objects, etc. to the single-level, string-based API provided
by the library).
In spite of that shortcoming, the library itself works reasonably well.
It does a very good job of extracting text from most documents I've
thrown at it, and it almost never crashes (at this point, I've extracted
text from a couple million documents using the library, and seen fewer
than a dozen crashes). Of course, I'd rather it not crash at all, but I
have come to have relatively low expectations of third-party software.
They have a free trial, so you can easily see if it suits your needs.
There are other libraries out there that do similar things. A
Bing/Google search will easily show you them.
Pete
