I am using PDF Clown for this purpose.
I wanted to add fields in PDF document. Actually I have successfully added fields in portrait PDF documents but doing the same in Landscape PDF documents is troubling.
Controls are placed vertically instead of horizontally.
Please help in this matter even if your proposed solution is using any other library. I will be very thankful.
Regards,
Mujtaba Panjwani
PS. I have tried PDFSharp.NET but that seems to have no support for creating fields and for iTextsharp, I am not sure.
iTextSharp should do the trick. Have a look at the many examples available on their website.