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I have a C application from a third party vendor,which I have to convert into a DLL.
For this purpose I have exported a function from the app as
__declspec(dllexport) char* maindllentrypoint(int argc, char* argv[]);
And i build the app has a DLL.
But I get 'access violation' error for malloc.
char* maindllentrypoint(int argc, char* argv[])
{
char* strData;
strData=malloc(24);
return strData;
}
So I think the C run-tie is not getting initialised properly.
So I put an entry point to the DLL(though I am not sure whether it is required)
BOOL WINAPI DllMain(
HINSTANCE hinstDLL, // handle to DLL module
DWORD fdwReason, // reason for calling function
LPVOID lpReserved ) // reserved
{
// Perform actions based on the reason for calling.
switch( fdwReason )
{
case DLL_PROCESS_ATTACH:
// Initialize once for each new process.
// Return FALSE to fail DLL load.
break;
case DLL_THREAD_ATTACH:
// Do thread-specific initialization.
break;
case DLL_THREAD_DETACH:
// Do thread-specific cleanup.
break;
case DLL_PROCESS_DETACH:
// Perform any necessary cleanup.
break;
}
return TRUE; // Successful DLL_PROCESS_ATTACH.
}
But I still get the error.My C run-time is linked statically with /MT option.
How do i prevent this crash?
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Hello All,
I am working on an application not using MFC and is there any way I can get the memory statistics. The MFC supports CMemoryState structure. How can I use CMemoryState in an application not using MFC? Or is there a way to convert an application "Not using MFC" to "Use MFC in a shared DLL" ?
Thanks,
Prathima
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You can look at the functions available in
#include <crtdbg.h>
<B>Sonork 100.41263:Anthony_Yio
</b>
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Dear All
I have used MSFlexGrid in my application... I want to draw figures in msflexgrid cell.
How to do that ? can i get the CRect of flexgrid cell ?
can i get DC of flexgrid cell?
Thanks in adnvance
kamal
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 Hi,
can anyone tell me.. there is a program..where an exe is dependent on some of the libraries (which are also being created by the program itself some other modules in same program creates these libs and dlls)..it runs fine in release mode but when i try to run it in debug mode so that i can check some variables and values and can change it accordingly..it fails showing me some errors like loading failed of the library.. what cud be the possible reason and how to make it run in debug mode..any ideas..any pointers are highly appreciated..
thanks a lot in advance..
regards,
Himanshu
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make sure thart the libs-dlls are also of debug version for the debug build of ur application.
hope this will help
rgds..mil10.
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i have written an application which responds to log off and shutdown seperately. In both the cases i make some boolean registry entry for the next run of the application. When i log off, i make the registry entry as 0, and on shutdown as 1. I make the entry as 0 on log-off to logically mean that my application is running, so that on log-on when i click on my app, it shows the running state. and vise-versa for shut-down. Now if i log-off and then shut down without logging in, the registry entry is unchanged(i mean the entry remains at 0). so when i start the system, and i click on the application, it shows to be in the running state athough actually it is not. how do i resolve the matter of log-off and then shutdown, instead of a direct shutdown.
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Hi,
Does anybody have the source code based on the Khalid Sayood's Arithmetic Coding algorithm?
Thank you so much!
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i have developed an appication which i want to start
when the system boots. it is a network access control application and hence i want to start it immediately after the system boots. i have made a registry (string) entry in
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
so that my application runs at start time.
but i found that this entry only starts the application only after i log-in. But i want to start the application before login, how do i do?
actually i m starting a driver(written by me) through this VC++ application. as such i want load the driver before i login,i.e., immediately after the system boots. wat should i do?
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If you change your application to a service it will run before login.
Ant.
I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)
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how do i change my application to a service. it is a MFC application. any links?
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wat is the message sent out when a user logs in to a system. just like WM_ENDSESSION is send when a system shuts down, similarly wat is the message when a user logs in?
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Hello,
When I have a Handle(HWND) to an Object
or in the Window I can Send a Message for It.
But if I save this Handle to a File after running
the Window again, I can't Use the saved handle to
send message to it.
is there any way to save a handle or something like
that and use it again?
Best Wushes.
Thanks.
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a handle is created dynamically at runtime by windows. not a good thing to depend on. dont save the hwnd. instead, use some other means like FindWindow()
Bikram Singh
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Dear all,
I'm developing an SNMP manager using WinSNMP API. While starting up the SNMP by calling the function SnmpStartup, it returns SNMPAPI_SUCCESS, but strangely the 5 output parameters are not defined after the function is executed. Is this normal? Why is this happenning? What should I do?
Regards,
Alan Lewis
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It's been a while since I've done MFC and I thought there used to be a header file that you could download from CP that would do some compiler optimizing for you. Does anybody know what I'm talking about or was I thinking of something else?
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Hi
Let's say I have a class A. A has a static member whose type is another class, let's call it class B. Usually in my C++ application I declare this static member at the top of A's .cpp file as follows:
B A::instanceofB(aString)
where aString is of std::string type and is the argument for B's constructor.
That works OK and I got the result I wanted. However, yesterday I use that file on a different project (it's a directshow filter project) and it seems that instanceofB is never initialized there! I tried to debug it by making B's constructor to write to a file, but when I checked, the file was never written into, it's as if B's constructor's never called at all. I did that for B's default constructor too, but with the same result. I checked in all the project settings but I couldn't find out what causes this discrepancy.
Could someone point me on what's the possible causes for this?
Thanks!
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what about putting breakpoints in B's constructor? Or could you maybe declare the instanceofB inside A's constructor?. Maybe the compiler did realized that instanceofB was never used and therefore no code was generated?
modified 26-Oct-22 21:01pm.
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Indrawati wrote:
Let's say I have a class A. A has a static member whose type is another class, let's call it class B. Usually in my C++ application I declare this static member at the top of A's .cpp file as follows:
B A::instanceofB(aString)
where aString is of std::string type and is the argument for B's constructor.
That works OK and I got the result I wanted. However, ... it seems that instanceofB is never initialized there!
Where/how/when is aString initialized - i hope it's before instanceofB. If not then instanceofB is initialized (at best) with an empty string.
This alone is a potential problem. This is why you try to not to polute the global pool, especially with complex objects, especially with complex constructors.
You have little control over the order globals are initialized across modules.
Basically (if i remember right) globals within a module (c/cpp file) are initialized in the order they appear. Modules have their globals initialized in an effectively undefined order. That is, you don't know if a.cpp globals are initialized before or after b.cpp globals.
You can define some control over this using the #pragma init_seg(...).
#pragma init_seg(compiler) - initialized 1st
#pragma init_seg(lib) - initialized 2nd
#pragma init_seg(user) - initialized 3rd
#pragma init_seg(my_seg) - all initialized after user, but in no other defined order
The main limits with the above are :
- you should really never use compiler unless you know what you are doing
- you can only really use init_seg() once per module and it applies to all globals that follow
This may not be the problem.
Another thing to look at is if instanceofB is being linked in - with the little info provided i can't see why it wouldn't though.
Another thing is that the file i/o state may not be initialized by the time you try to initialize instanceofB. This would prevent B::B() from writing to a file. Try using OutputDebugString().
...cmk
Save the whales - collect the whole set
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Hi
aString is a global constant defined in a separate header file. Actually, I defined it as follows:
const char *const aString = "anything";
I *think* it should be no problem.
Could you please elaborate on the second potential problem (about instanceofB being linked in), since I'm not very clear about it?
Thanks!
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I'm not exactly sure if I really want a custom control, but here is what I am trying to do.
Currently, we plot points on a graph. The points are stored in a vector of POINTs and are simply drawn on the screen (dc.SetPixel and dc.Ellipse). A new requirement has been added to allow users to move the points. I can either check the entire vector on a LButtonDown to see if the mouse click point matches an item in the vector or...what I am hoping is to create a new type of CCmdTarget class or CWnd so I get messages built-in. Essentially I want to create a new Point class which knows about receiving point clicks, mouse movements, etc. The idea is to move the burden of figuring out mouse clicks/moves to this new Point class.
Any help is greatly appreciated. Thanks. I figure this has been done before, but I could not find anything by doing an article search.
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I cannot figure out how to get a CToolbar to show multiline strings.
I can SetButtonText, but I cannot ever get the second line to show.
This doesn't work:
<br />
m_myToolbar.GetToolBarCtrl().SetDrawTextFlags(DT_CENTER, DT_CENTER);<br />
m_myToolbar.SetButtons(NULL, 1);<br />
m_myToolbar.SetSizes(CSize(80, 80), CSize(1, 1));<br />
m_myToolbar.SetButtonText(0, "Line1\n Line2");<br />
Any help would be greatly appreciated!
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Hello all gurus..
If I want to create the string that contains given digit like 3 for 3 digit in the string, how should i done it?
To clear what I'm trying to say, here is an example.
CString prefix = "pf";
int numDigit = 6;
int startNum = 1;
CString k;
k.Format("%d%d",numDigit,startNum);
k = prefix + k;
the output that I want is:
k = "pf0001"
I know I'm doing it wrong.. coz the answer wasn't the one i want it and is there any other way instead of using for or while loop, counting numberDigit.
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Try this. It works.
CString prefix = "pf";<br />
int numDigit = 6;<br />
int startNum = 1;<br />
<br />
CString k;<br />
k.Format("%0*d",numDigit-prefix.GetLength(),startNum);<br />
k = prefix + k;<br />
cout << (LPCTSTR) k;
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