Sorry bout the confusion w/ the name of the API I specified - I was thinking about FindFirstChangeNotification when I wrote the e-mail, when I wanted to write "ReadDirectoryChanges" instead!!
That's what I'm actually after, the API "ReadDirectoryChanges"... Thanks. ________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Rob Kennedy Sent: Tuesday, 2 August 2005 5:48 AM To: [email protected] Subject: Re: [delphi-en] ReadChangeNotification API Brad Hall wrote: > Does anyone have any eg's of the "ReadChangeNotification" Win API? I > want to implement it into a prog I have, but the Web hasn't been as > helpful as I thought on this one... Perhaps that's because there's no such thing as ReadChangeNotification. Try you search using the correct name, FindFirstChangeNotification, and see whether that helps. Also try the classes in the VirtualShellNotifier unit, part of Jim Kueneman's free Virtual Shell Tools package. http://www.mustangpeak.net/ > And does the API run in the background of my prog so that my prog can > continue to execute as normal, or am I going to have to thread the API > call (I read something about a Wait state)? FindFirstChangeNotification returns a handle. To be notified that a change has occured, you need to wait on that handle. WaitForSingleObject is the easiest way to wait, but it's also a blocking call. The thread that calls that function won't do anything else until the change notification is satisfied, so you'll need to use a separate thread for that. When your program terminates, you'll want to tell the waiting thread that it should stop waiting. To do that, you'll need to have a way of waking it up without changing the file system. Instead of WaitForSingleObject, use WaitForMultipleObjects. In addition to the change-notification handle, you can also use an event handle (see CreateEvent). When the main thread want the notification thread to terminate, it can signal the event, which will cause WaitForMultipleObjects to stop waiting. There is a way to do all this without a separate thread, but it gets much more complicated, and Delphi wasn't really designed to work this way. You can wait on handles while still handling messages y calling MsgWaitForMultipleObjects. It stops blocking when a message arrives, at which point you can call Application.ProcessMessages and then resume waiting. If you have a dialog box or modal form open, then there is a separate message loop active, and that loop doesn't know about the handles you're waiting on, so certain events might go unnotices for a while. I think a separate thread is much easier to work with. -- Rob ----------------------------------------------------- Home page: http://groups.yahoo.com/group/delphi-en/ To unsubscribe: [EMAIL PROTECTED] ________________________________ YAHOO! GROUPS LINKS * Visit your group "delphi-en <http://groups.yahoo.com/group/delphi-en> " on the web. * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> . ________________________________ [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> <font face=arial size=-1><a href="http://us.ard.yahoo.com/SIG=12hlakbuf/M=362131.6882499.7825260.1510227/D=groups/S=1705115362:TM/Y=YAHOO/EXP=1122946602/A=2889191/R=0/SIG=10r90krvo/*http://www.thebeehive.org ">Get Bzzzy! (real tools to help you find a job) Welcome to the Sweet Life - brought to you by One Economy</a>.</font> --------------------------------------------------------------------~-> ----------------------------------------------------- Home page: http://groups.yahoo.com/group/delphi-en/ To unsubscribe: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/delphi-en/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
