There is an rtf file. You need to open it and write each page to your richtextbox . It is required to write it in richtextbox.rtf so that the formatting and all the tables are preserved. How is this possible to implement?
upd. I did this as follows: I opened the rtf file in the temporary richtextbox, wrote it in the string variable str = richtextbox.rtf, after richtextbox.text = str. and further in the text I searched for a page break (in rtf a page break "\ page"), copied an rtf header in which the font, font size, etc. were indicated, and added what was between breaks, then assigned the resulting string to the desired richtextbox.rtf