Using OpenXML, can I read the document content by page number?
wordDocument.MainDocumentPart.Document.Body gives content of full document.
You cannot reference OOXML content via page numbering at the OOXML data level alone.
What about w:lastRenderedPageBreak, which is a record of the position of a soft page break at the time the document was last rendered? No, w:lastRenderedPageBreak does not help in general either because:
w:lastRenderedPageBreak position is stale when content has
been changed since last opened by a program that paginates its
content.w:lastRenderedPageBreak is known to be unreliable in various circumstances including
If you're willing to accept a dependence on Word Automation, with all of its inherent licensing and server operation limitations, then you have a chance of determining page boundaries, page numberings, page counts, etc.
Otherwise, the only real answer is to move beyond page-based referencing frameworks that are dependent upon proprietary, implementation-specific pagination algorithms.