How to read pdf file in c# windows application.....

Thanks in advance

iText library is what you may want to try. It has support for Java and C#

Actually i tried Itextsharp lib. but not found any source code to read pdf file line by line.

Usually you do not read PDF line by line. You have to read document (in Java PdfReader), then using high-level objects such as Chunk, Phrase, Paragraph, List, and so on you can access elements of page. These objects are often referred to as iText's basic building blocks.
However this may not work properly in case that PDF document is converted bunch of images (usually the case after scanning the documents) as these would need OCR process (Optical Character Recognition)