C / C++ / MFC

JennyP20-Jul-02 10:14

JennyP

20-Jul-02 10:14

Thanks for the tip. I could not find the ALK key in the virtual key typedefs, but I did find VkKeyScanEx() through the MSDN links. That function seems to have a way to read the ALT key state.

JennyP

C^hris L^osinger20-Jul-02 10:34

20-Jul-02 10:34

it's called VK_MENU (not VK_ALT)

-c

To explain Donald Knuth's relevance to computing is like explaining Paul's relevance to the Catholic Church. He isn't God, he isn't the Son of God, but he was sent by God to explain God to the masses.
/. #3848917

Jason Hooper20-Jul-02 11:52

Jason Hooper

20-Jul-02 11:52

I just read about this today, myself. Hail Petzold!

- Jason
(SonorkID 100.611)

In the beginning, teachers taught the 5 W's: who, what, where, when, why. Now it's just a big damn G

Re: DLL Problem !!! Plz help

JennyP20-Jul-02 11:56

JennyP

20-Jul-02 11:56

Oh, I didn't realize! Thanks! Smile | :)

JennyP

std::strstream

User 988520-Jul-02 9:18

User 9885

20-Jul-02 9:18

I use this class in an app to format strings.

But, when I exit the app in debug mode, I see the strings that I formatted as memory leaks. What should I do to remove these memory leaks?

now the code looks like this:

void function()
{
std::strstream ostr;
ostr << "This is a test" << std::ends;
// i use the ostr
// i assumed that the cleanup would happen when function quits
// but when i quit the app, I can see the "This is a test" in object dump
}

modified 29-Aug-18 21:01pm.

Re: std::strstream

Rama Krishna Vavilala20-Jul-02 12:02

Rama Krishna Vavilala

20-Jul-02 12:02

Don't use strstream it is outdated now. use stringstream

Step back, rub your eyes, take a deep breath, stretch a bit, and reflect on the relative importance of CP, CG, the age / travel time sustained by supposedly 'fresh' cheese curds, and Life in General. - Shog⁹

Re: std::strstream

Todd Smith23-Jul-02 13:29

Todd Smith

23-Jul-02 13:29

Call

ostr.freeze(false);

Todd Smith

DLL Problem !!! Plz help

jancsi20-Jul-02 8:26

jancsi

20-Jul-02 8:26

I have created a regular dll which export the function
__declspec(dllexport) BOOL Extract(PCLTextList *pList);

A create and pass to the dll the pList pointer from a Dialog Based application . When I call delete PList from this app an ASSERTION FAILED Error appears at this function:
_CrtIsValidHeapPointer

Does anyone know why?

Plese help if you can

Thanks
Jancsi

xxx

Dudi Avramov21-Jul-02 1:33

Dudi Avramov

21-Jul-02 1:33

Correct me if i am wrong:
someone creates a list object , sends it to your dll and you fail to delete that object.
If that so, then check whether your run-time library and the caller run-time library are the same.
For example, if your run-time library is Multithread Dll (/MD) and the caller run-time library is Multithread (/Mt).
Check what happens when the caller's project and your project have the same run-time library.

Dudi

Re: DLL Problem !!! Plz help

Daniel Lohmann21-Jul-02 1:53

Daniel Lohmann

21-Jul-02 1:53

Dudi Avramov wrote:
Correct me if i am wrong:
someone creates a list object , sends it to your dll and you fail to delete that object.
If that so, then check whether your run-time library and the caller run-time library are the same.
For example, if your run-time library is Multithread Dll (/MD) and the caller run-time library is Multithread (/Mt).
Check what happens when the caller's project and your project have the same run-time library.

Uh, oh - this works only if both the .dll and the .exe use the same DLL-Version of the CRT. It will fail if they are linked against the static version.
The reason is the following: The CRT contains a heap manager, which implements operators new and delete. If you link the CRT statically to a module (.exe or .dll) the heap manager is also linked to your module, meaning that each module contains its own heap manager. It is not possible to allocate memory from one heap manager and delete it with another one - they don't know of each other and the memory just looks invalid to them. And this is what happens in your project.

However, if both, the .dll and the .exe are linked to the same DLL-Version of CRT, they share the same heap manager (because the CRT DLL is loaded only once into the process' address space). Then all ressources (memory, open file handles, etc.) are interchangeable between the modules.

To avoid this messy details it is common and good practise to destroy resources always in the same module they have been allocated. Then the used CRT version does not matter and you are always on the safe side Smile | :)

--

Daniel Lohmann

http://www.losoft.de

MFC project on XP - wont work!

ns20-Jul-02 7:48

20-Jul-02 7:48

I'm developing in MFC on Win2k. It does fine at work, but when I took it home to XP,it debug asserted immediately! I was disgusted and didnt even start debugging to see where it crashes. SoI am thinking of getting another 80Gig hard drive and dual booting with XP and Win2K. I did load another MFC project developed on Win2K onto the XP and that one did fine. ANy ideas?

Thanks,
ns

C^hris L^osinger20-Jul-02 8:26

20-Jul-02 8:26

find out where and why the assertion occurs.

-c

ns20-Jul-02 8:32

20-Jul-02 8:32

Okay. so I'll put a breakpoint first in the apps initinstance, then if it goes through okay, in the mainframes init then the chids init then the views init etc I guess - since i iamgine thats the flow of things....ANy sugggestions about the debugging (I'm still feeling my way through this - crashes are terrifying!)Thanks very much for the response,
ns

C^hris L^osinger20-Jul-02 8:34

20-Jul-02 8:34

just run the app in the debugger and let it hit the assert. when it does, press Retry and see where you end up.

-c

Re: MFC project on XP - Rebuild All resolved it!

ns22-Jul-02 3:50

22-Jul-02 3:50

I was just about to go buy a second HD to dual boot to win2K, anf thought I'd try "rebuild all" in a last desparate attempt. I almost fell out of my chair when it worked!
Whew!
Incidentally , doing retry on the assert just told me that VS was not happy, and did I want to send a report to MS. Then it went back to the place where I last left my cursor, so that gave me no hints as to the problem location...
Thank you so much though!
ns

VC.net and Distribution issues

Alexandru Savescu21-Jul-02 9:08

Alexandru Savescu

21-Jul-02 9:08

ns wrote:
but when I took it home to XP,it debug asserted immediately! I was disgusted and didnt even start debugging to see where it crashes.

I'd like to be able to tell my boss that. "It doesn't work at all, I didn't even bother to start debugging"...

Best regards,
Alexandru Savescu

Sumudu Perera20-Jul-02 7:10

Sumudu Perera

20-Jul-02 7:10

I'm studying in an Australian Education Center. They have Visual Studio .NET Enterprise Architect installed. I've heard a rumor about apps compiled with VS carrying a digital signature with the product ID of VS IDE. Is this true? So, if I use this copy to build an app, and try to sell it on the web, would I get into to trouble? Especially, since I don't own this copy?
Would I be off the hook, if I make it a freeware? Rose | [Rose]

Re: VC.net and Distribution issues

C^hris L^osinger20-Jul-02 8:28

20-Jul-02 8:28

sounds like you should ask the AEC, or find out what their license says.

-c

AppendMenu problem !

Hadi Rezaee20-Jul-02 6:59

Hadi Rezaee

20-Jul-02 6:59

Hi there,
I loaded menu from my project resource …
I have not problem in loading or displaying this menu …
But when I want to add new item to loaded menu … my code don't works !

CMenu menu;
menu.LoadMenu(IDR_MENU1);
.
.
.
menu.AppendMenu(MF_SEPARATOR);

// Display menu …

What's wrong ?

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Hadi Rezaie

Re: AppendMenu problem !

C^hris L^osinger20-Jul-02 8:29

20-Jul-02 8:29

try adding your items like this:

CMenu* pPopup = menu.GetSubMenu(0);
pPopup->AppendMenu(...)

this is how i do it for all my context menus.

-c