Remove(delete) objects outside page area(eg. cropbox)

Product: PDFNet SDK

Product Version: 10

Please give a brief summary of your issue:
Remove(delete) objects outside page area(eg. cropbox)

Please describe your issue and provide steps to reproduce it:
I did some research and find that the Adobe Acrobat Pro can do this,you can see below:

This is my example file:
remove page content outsid crop box.pdf (9.8 KB)

Open this file in Acrobat Pro,press the edit button,and you will see the content not int the page visible area.

So, how to delete all the content outside the rect with PDFNet SDK?
Thanks very much!

waitting for help…

thanks …