PDF text position, page left margin - itext

Question

I want to write an application to validate a PDF file. The validation that is required is to verify that all the text and images in the PDF should start after 0.5" margin from left and 0.5" margin from the right. If any of the text is going outside this margin then application should be able to catch this.
I tried to search this into iText but couldn't get anything usefull that can solve my purpose.
Can somebody help me out in writing this code in .net csharp.
Thanks,
Praveen

Answer 1

In addition to R Ubben's answer : reader.getPageSize(pageNumber) is exactly the same as reader.getBoxSize(pageNumber,"media").
That's how it's implemented in iTextSharp. You can see it in source code.
Extract:
public Rectangle GetPageSize(PdfDictionary page) {
PdfArray mediaBox = page.GetAsArray(PdfName.MEDIABOX);
return GetNormalizedRectangle(mediaBox);
}

Answer 2

use SetMarginMirroring(true)

Answer 3

The PDF standard doesn't really have the concept of margins, since a PDF is supposed to be device independent. What it can have is five boxes designed to constrain output: media box, crop box, bleed box, art box, and trim box. Usually the other four boxes are the same size or smaller than the media box.
If a mediabox is present in your pdfs, you could retrieve it and check to see that it is 0.5" smaller on each side than the page. Try comparing the results of reader.getPageSize(pageNumber) and reader.getBoxSize(pageNumber,"media"). Very likely they will be the same.
What you can do is rewrite the pdfs to make sure there are 1/2 inch margins. The easiest way to this is shrink the page.