Still learning how to code wrote: My Arduino code expects time quantities to be received as localtime (i.e. adjusted for DST) You should change that to UTC if possible. When your Arduino uses a different time zone than your Windows system, the results would be wrong again.

I am not seeing this issue. I get 4 for unResult. Do you have your floating point options set correctly in the compiler? In visual studio, select properties on your C project. Expand the projects setting out for "c/C++->Code Generation" and set the option for "Floating Point Model" to Precise(/fp:precise).

Still learning how to code wrote: I picked up a function RecursiveDelete on the internet, as I needed to erase all files and folders on an SD card... Why not just use SHFileOperation() with the FO_DELETE operation? "One man's wage rise is another man's price increase." - Harold Wilson "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

Hello David, Thanks for your reply ! I have tried your suggestion but this change produces the command line "D:\StickCopier\deveject -EjectName:""USB Mass Storage Device""" in the debugger (i.e. a PAIR of double quotes whereas single double quotes are needed for the argument to EjectName:) Since my original posting, I have tried ShellExecute() and am getting a similar result - ShellExecute() succeeds (RC = 42, which is greater than 33), but the USB stick is still mounted. New code is as follows:- CString szFile = "D:\\\\StickCopier\\\\deveject.exe"; const CString quote = "\\""; // This is actually the character '"' CString szParameters = "-EjectName:" + quote + "USB Mass Storage Device" + quote; CString szDirectory = "D:\\\\StickCopier\\\\"; HINSTANCE hInstance; hInstance = ShellExecute(NULL,"Open",szFile, szParameters, szDirectory,SW\_HIDE); // returns 42 (> 33 so no error Doug

Found the "problem" ! (Embarresing really !) I wrote this app a long time ago and used a dialog-based MFC app but prevented the dialog appearing so that it effectively ran in the background. The main "routine" was in InitDialog() and effectively prevented messages being handled by the "window". Now create a thread in InitDialog(), let it complete, and hide the window in another way. WM_QUERYENDSESSION is now handled, and all works fine ! Thanks for your thought-provoking comments !! :) Doug

Of course ! (Just going though the code now, and beginning to see how to about this) Thanks for your help ! Doug

Hi Richard, As you can see from an earlier message on the thread, I had accidently tripped myself up ! I'm all sorted now - thanks anyway ! Doug

>>Param holds the pointer to the text, and is assumed to be a valid pointer within the process' address space. It can not be an address in some other process.<< Thanks for your patience, Luc !! So that I can just FULLY understand this, let me describe it back to you with a few extra words (!!):- The issuer of SendMessage() holds the variable containing the text (my app, in this case), and lParam is set up containing an address to this variable (within the senders address space ?). The receiver of SendMessage()(the 3rd party app, with which i'm endeavouring to interact) has access to lParam which contains the address of the original text, but as I'm alluding to above, is this address within the sender's address space ? I suspect that somewhere within the process, the text is COPIED to some global address space and it is THIS address that is contained within lParam. I can't see how else the process can work whilst protecting each app's memory space. I await your words of wisdom, and to be "sorted out" !! Again, thanks for your patience ! Doug

Hi Paul, What a brilliantly comprehensive answer ! Very many thanks ! :-D :-D :-D :thumbsup: Doug

Hi Garth,   I think that the real problem is that the folder that I want to watch is on a NAS disk and so the "This code will only work on Windows NT, Windows 2000, or Windows XP, and the directory you wish to watch must also reside on a WindowsNT, Windows 2000, or Windows XP computer" is going to make it a non-starter.   I've now implemented a polling _findfirst/_findnext strategy which, although a bit basic, works fine !!   (Just hope that the NAS disk can stand the traffic !!) Many thanks for your determination to find me a solution !!! Cheers ! Doug

For anybody that hits this problem, I thought that I would update this thread.   By a process of trial and error, I found that the only class of my project that would recognise the WM_POWERBROADCAST message was CMainFrame (by overriding WindowProc()   ) Doug

Adam/Cedric,   Thank you for your advice !   All fixed now - put it down to ignorance !! :-D Doug

I got the same problem as you have, but never found a solution. Thaught then that it was because i use Linux with Samba as the networkserver. Rozis

Have a look here[^] for a more descriptive explanation of what Joe is talking about. You'll also find a lot of things that are Really Good To Know regarding multithreading in the article. "It's supposed to be hard, otherwise anybody could do it!" - selfquote "High speed never compensates for wrong direction!" - unknown

Thanks for both replies !! Yes, the use was within a global function (Timer callback) and the use of CWnd:: has cured the problem. Just given myself a smacked hand for not trying that before posting the cry for help !! Thanks again ! Doug

DavidCrow wrote: Could it be that OnDraw() is called so often that CLogFile code can't keep up? Don't see how - I'm running to a break point on the LogFile->Add() function within OnDraw(). Invoke second refresh of screen by maximising it, and off we go through the path that I described earlier and end up at that Call to bad assembler code. Are there any "no, no's " for code within OnDraw() or in OnPrepareDC() functions, or any timing restrictions (we obviously have to access a file) ??? Doug

Heh - nah it's not that obvious....The docs aren't real clear on this if I remember right. The source code is better documentation. :) Mark Mark Salsbery Microsoft MVP - Visual C++ :java:

Just discovered that this is fixed by:- NETRESOURCE = { '\0' }; :-D :-D :-D Doug

Perhaps, I should have emphasised the question in my mind - "Do I have to do anything within the OS (Win2K) to allow the wakeup to occur" ? Doug

Does anyone have any comments on my last posting ? :confused: Doug