Debenu Quick PDF Library - PDF SDK Community Forum : DARenderPageToDC() slowing down form processing. http://www.quickpdf.org/forum/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Sat, 04 Apr 2026 17:42:33 +0000 Sun, 06 Jun 2010 23:47:31 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 11.01 360 www.quickpdf.org/forum/RSS_post_feed.asp?TID=1474 <![CDATA[Debenu Quick PDF Library - PDF SDK Community Forum]]> http://www.quickpdf.org/forum/forum_images/QPDF_Forum_Title.png http://www.quickpdf.org/forum/ <![CDATA[DARenderPageToDC() slowing down form processing. : I am using QuickPDF&#039;s DARenderPageToDC()...]]> http://www.quickpdf.org/forum/darenderpagetodc-slowing-down-form-processing_topic1474_post6614.html#6614 Author: Roulette
Subject: 1474
Posted: 06 Jun 10 at 11:47PM

I am using QuickPDF's DARenderPageToDC() function in a background thread in a form-based application.  I have tried setting the background thread to ThreadPriority.Lowest.  Despite that, when QuickPDF is rendering (to an HDC that is never displayed) processing events on the form becomes very sluggish, often taking over a second to register things like button clicks or moving the form to a new location on the screen.
 
I am on an Intel i5 750 (2.67 GHz quad-core) and there are no other background threads running.  If I disable the single DARenderPageToDC() line (and leave in the rest of what happens in the background thread such as opening the PDF, retrieving the number of pages, saving the image via a custom function, etc.) the form registers events as quickly as you would expect.
 
Any ideas as to how to use DARenderPageToDC() in a way that is more friendly in a multi-threaded application?  I'm assuming that function must be multi-threaded?  Can someone confirm that and, if so, what priority are its child threads?
 
- Roulette
 
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