I am updating an old MFC application that used WinHelp so that it now uses HtmlHelp. I've changed the constructor of CWinApp-based class so that it calls EnableHtmlHelp(). Then I've changed the old calls from WinHelp( IDH_CONTENTS, HELP_CONTEXT) to HtmlHelp( IDH_CONTENTS, HH_HELP_CONTEXT). Unfortunately, whenever I try to open the help from my application, I see the help window appear and then it and my application immediately close. If I step through the code line-by-line, the help file appears and stays visible. Does anybody have any idea what's happening here and how I can fix it? Thanks.
Ok. I found it. I finally paid attention to this statement in the MSDN documentation:
When using the HTML Help API, set the
stack size of the hosting executable
to at least 100k. If the defined stack
size is too small, then the thread
created to run HTML Help will also be
created with this stack size, and
failure could result.
I changed my project settings to remove the Stack Reserve Size and now the help opens correctly.
Related
So I have spent that past week and a half working on code to simply setup the hook procedure for wh_shell for a program that will replace explorer.exe in the registry and will run as the main desktop program. There seems to be very little information and sources for using this outside of just the windows API which is a bit undescriptive and doesn't explain everything to a great detail. For some reason I just cant get it to work, no matter if I run it inside of explorer.exe, or if I replace the register and make it the default shell. I'm going to ask a couple of things in this post because I think that if you can answer one of these questions you likely have the answer to more.
So first I just have a question about hooks in general: When I run the SetWindowsHookEx(...) function -resource below- it says for var lpfn that a dll is not necessary if the hook is only used to monitor the current process. Now obviously when monitoring events such as window_created, those are events within a different processes which makes me think that the hookproc has to be within a DLL(which is how ive programmed so far). But this is questionable to me because when u are running SetWindowsHookEx(...) the process I wish to monitor do not yet exist until the user decides to start them. Do these processes notify the system when wh_shell events are being done so that I my hook doesnt need to get placed into every process upon creation, or is it more like when I run SetWindowsHookEx(...) with wh_shell that it will place a hook in all processes when the are created. The second resource states that the system just calls the hookproc when these things happen, so then do I even need a DLL, or what process does it need to be hooked to because I dont think it needs to be hooked into everything.
So second I have a question regarding setting my process as default shell - see resources - the resource states any process that registers itself as the default shell(which I assume is just modifying the registry to my process, if not and there is more please let me know) needs to call the SystemsParameterInfo(...) function. So first, does this func need to be called before running SetWindowsHookEx(...) or is there some expected spot it should be elsewhere in my code? Then in regards to the other variables it doesnt specify for, just curious what the recommended would be to set them as, like what are they set as for explorer.exe, and maybe a few other examples(including things NOT to do).
Finally for the sake of testing, using the console will be the most helpful to me here. The console will be used for input to run functions and commands for now(like open the register and swap back the shell to explorer.exe). If my hookproc is within a DLL, I need it to output some messages, I dont want to muddle the same console and I also dont even know if it will output to the same console, so what might be a recommended or potential solution for outputs(again this is temporary and for testing so it doesnt have to be perfect or even great)?
Also I would think windows 11 shouldn't be an issue, but I havent tested on windows 10 system...
I havent included any code as Im pretty sure most of this stuff can be answered without it and that its so few lines of code that its not like typical questions where its like examine my code and help me, maybe some example code you can show me would be really helpful.
Thankyou!
SetWindowsHookEx(...)
https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-setwindowshookexa
defaultShell
https://learn.microsoft.com/en-us/windows/win32/winmsg/about-hooks#wh_shell
regards to WH_SHELL section
Testing Environment:
Windows 11 vm running in Hyper-V Manager
You haven't mentioned an important parameter in your description and that is the last argument of SetWindowsHookEx, the thread id.
When it is set to 0 then ..
'[in] Specifies the identifier of the thread with which the hook procedure is to be associated. If this parameter is zero, the hook procedure is associated with all existing threads running in the same desktop as the calling thread.'
That said, then like everything in Windows programming nothing is as what the documentation states, its as if the documentation is a wish-list Microsoft will like Windows to be when it grows up.
Actually even if you manage to get everything right you will see that the shell messages you will get will be VERY few compared to what the documentation states.
I am working on the same issue and when I get it going I will post the results here.
When I'm running any project in Code Blocks I see this:
or
What should i do?
Thank you for your question and for using CodeBlocks as IDE.
The error message you are getting is because codeBlocks has no 'write' privileges to the folder where it wants to place the binary (or executable). You need to change the privileges of the folder where you ave your projects stored to Read/Write/Execute for all.
If you need to know how to do that, you need to put the specs of your system in the comments, I will tell you here on how to.
KR
Hewi
You usually get this message when you try to recompile an executable that is already running.
If you got this error, you should simply close your application. If you can't see an application window and you're still getting the error, open Task manager (Ctrl+Shift+Esc), find your program in processes list and close it from here.
When running my asmjs\emscripten application, compiled from C++, it has suddenly started to log: "run() called, but dependencies remain, so not running" to the web console, and nothing more happens.
I've added some cout's at the absolute start of my main, but even they aren't reached.
The application executed successfully before, but suddenly this started to happen and I don't know what change triggered this.
Does anyone know how to debug this?
Update
After removing as much source code as I could, this happens as soon as I #include , even due my main simply consists of a single cout.
Ideally you would have the entire environment when it was running in version control, and build every version since to see where it broke.
You might have your code in version control, but perhaps not Emscripten itself. If you've updated Emscripten, this could lead to differences in behaviour. I would try going back to whatever version you used when it was running. Note that sometimes various cache directories survive an Emscripten version change, and might need to be cleared manually (I forgot which exactly).
The dependencies remaining could mean that you are trying to do something before Emscripten has loaded any other files it needs to, say files requested by --preload-file or --memory-init-file. Note that according to https://kripken.github.io/emscripten-site/docs/getting_started/FAQ.html#faq-when-safe-to-call-compiled-functions you should not try to run any Emscripten functions, until the C++ main function has run. To detect this, you can, for example, call your own Javascript function from main (there are other ways).
The fact this wasn't causing a problem before could have been something that seems quite unrelated: a change or update in the web browser, changing limits of concurrent downloads, or a change in the web server this is running from. You could look in the Network tab in the browser to see if anything leaps out at you as being different or suspicious.
However, as main isn't even reached, then it might not be that. I would try commenting out virtually all of your code, and make it so you have practically nothing but a hello-world program. Perhaps you don't have a correct setting in the Module object, or maybe the request for the memory initialization file is failing (you can check in the Network tab in the browser for that one). If your basic hello world program still isn't working, then you could post again, with its code, in a separate question.
This can also happens when the browser runs out of memory. Unfortunately, the browser's memory handling is not in our control so there isn't much you can do beside reducing your payload. This includes code size, preload content size, etc. Basically anything that can reduce the total memory consumption of your program will help fixing this. Browser vendors are constantly working to improve this, but it's going to take a while still.
I think you haven't given enough information to really know for sure. But it might be for instance that your js suddenly crossed some memory threshold which exceeds what the browser wants to allocate to it. You could try reducing the amount of memory used / streaming some assets instead of preloading them / ship less code / use -Os optimization level?
We have a program which is proving difficult to debug. The MFC application runs fine for a few hours but over a day it will crash. Sometimes it will not throw any errors and simply exit the "dlg.DoModal()" section of our code without the user (or any obvious part of the code) closing the dialog. Other times it will crash and throw an error outside of our code and have a horrendous call stack that has nothing to do with our code, it has a lot of calls to system DLLs however.
A bit of background to our problem.
We are trying to develop a MFC bases C++ application (with a dialog). We have multiple threads and the code is rather large which makes debugging a nightmare. We have been experiencing intermittent crashes that we have been unable to locate the source of so far.
We are well past the use of breakpoints for debugging as we are pretty sure it is an issue somewhere in MFC, maybe not a bug but more a problem with the way we are using MFC.
Now we've tried simple things to help us like:
Enable all debug exceptions:
Debug -> Exceptions and then checking all the boxes so that we can
trap silly mistakes.
This proved helpful but we've now corrected all the errors it throws
within a few hours of running.
Search for memory leaks
We then tried Visual Leak Detector (which works beautifully by the
way) located here: http://vld.codeplex.com/ Our code now reports no
memory leaks so it is not an obvious memory leak issue. We have
included vld.h in the very top of our code near the entry point.
Adding Microsoft Symbol Server to obtain debug symbol files.
We then tried making our call stacks more human readable by using MS
Symbol servers shown in these tutorials:
http://social.msdn.microsoft.com/Forums/vstudio/en-US/3f1825e1-6770-48c0-91b0-12d8946ab259/2-how-do-i-configure-visual-studio-to-use-microsoft-symbol-server?forum=vsdebug and http://support.microsoft.com/kb/311503
This ultimately did nothing as it still doesn't tell you enough about any errors.
Using the Thread window to see all call stacks, and using the
Parallel Stack window
We have been using the Thread and Parallel stack windows to aid our
debugging but ultimately they have proved nothing more than pretty
pictures and fancily formatted call stacks that makes you feel good
more than anything. We have been using the tutorial here which has
been very handy
http://www.codeproject.com/Articles/79508/Mastering-Debugging-in-Visual-Studio-A-Beginn
Now for the more interesting things we've tried that do not throw errors straight away but can be detected as problems:
GDI Objects not being destroyed
This one is not obvious in VS2010 as an issue. Basically if you use a call like "CDC* pDC = lChild->GetDC();" and do not use the call "ReleaseDC(pDC);" then you have just created a GDI Object that will not be destroyed until your program terminates. VS2010 is a bit dumb in this regard and will keep creating these objects until your program crashes, and the call stack will look horrible and you will probably have no idea why it has crashed.
To find this issue, start Windows Task Manager -> Click Processes Tab -> Click the View Toolbar item -> Select Columns. Now check Handles, Threads, User Objects, and GDI Objects. Now start your program, find it's process in the list under Image Name, and watch to see if the GDI Objects column keeps growing or stabilizes.
Objects Not being destroyed
This is another not so obvious error, if you create a bitmap like this: "reinterpret_cast(LoadImage( GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BITMAPNPR), IMAGE_BITMAP, 0, 0, 0))" and assign it straight to a picture control, the bitmap will not be destroyed if you assign another bitmap to this picture control using similar code. Instead you need to assign the above to a HBITMAP variable which you then need to destroy when you are done.
This situation can also arise if you create a font or colour in a similar fashion.
Now with all that being said, we have tried all the methods above and we still can't find our issue. Sometimes our program will exit normally and we won't be given any debug info (this is usually after is has been running overnight), other times our program will lockup the PC (tested on multiple PCs), other times it will throw an error but we can't locate the culprit because it simply points to the ".DoModal()" part of our code and the rest is native windows DLLs which is useless for debugging purposes.
We suspect something is either being created and not destroyed properly but we aren't sure what and VS2010 is not telling us anything useful to point us in the right direction.
Does anyone have any ideas? How do we trap errors that aren't obvious to VS2010? Or rather how do we easily trap "GDI leaks" and the like?
Thanks in advance
Edit:
We've been using Microsoft's Application Verifier, it's found a few errors so far. To use it download it here http://www.microsoft.com/en-us/download/details.aspx?id=20028 run Application Verifier, add your .exe file in your Debug or Release directories and run the program in VS2010 as normal. VS2010 will break when Application Verifier 'sees' an error. It hasn't found anything too outrageous yet so I assume that we still have issues with our code.
I have an MFC application which needs to display a webpage. I've added a CHtmlView through CSingleDocTemplate which spawns a window and displays the page fine but it leaks memory when running javascript.
The page I'm looking at is genereated by Madcap flare and so it very heavy with javascript. I'm losing about 4K a second just sitting watching the page.
I've tried to reduce the problem by letting the user close the document but then I run into a problem with not knowing if the CFrameWnd was closed or not in the main application so not knowing if I need to create a new one or just reuse it.
I'm running this on windows 7 with IE9 installed so if I'm right I should be well clear of the old IE javascript circular references bug.
Does it happen in both Release and Debug build? I've seen similar (somewhat deterministic) errors when freeing dangling pointers or blowing the stack. With a bit of bad luck, the undefined behavior from faulty code could produce memory leaks.
Try enabling all possible runtime checks in your build and see if the error goes away (or is somehow detected).
Try commenting out large code blocks and see if the error goes away.
I'm just guessing here :)