C / C++ / MFC

29-Mar-07 3:51

DavidCrow wrote:
Keep it simple

True. I've just added one more thing.

[OT] I wonder, something is messed with posting, when i tried to post, its getting duplicated, and when tried to delete one of them, both are deleted.
[/OT]

Prasad
Notifier using ATL | Operator new[],delete[][^]

Ensure Correct Size

Programm3r29-Mar-07 1:57

Programm3r

29-Mar-07 1:57

Hi again,

When using the WriteFile function:

BOOL WriteFile(
  HANDLE hFile,                    // handle to file to write to
  LPCVOID lpBuffer,                // pointer to data to write to file
  DWORD nNumberOfBytesToWrite,     // number of bytes to write
  LPDWORD lpNumberOfBytesWritten,  // pointer to number of bytes written
  LPOVERLAPPED lpOverlapped        // pointer to structure for overlapped I/O
);

How can one be accurate on the nNumberOfBytesToWrite??
I have tried strlen() and sizeof, but still it writes out the whole buffer, and not just to the (null) '\0' character.
I have declare my buffer like this:

#define BUFFER_SIZE 100000
char buffer[BUFFER_SIZE]={0};

Thanx Again Smile | :)

Regards,

The only programmers that are better than C programmers are those who code in 1's and 0's..... Smile | :)

Programm3r
My Blog: ^_^

Re: Ensure Correct Size

prasad_som29-Mar-07 2:26

29-Mar-07 2:26

Programm3r wrote:
I have tried strlen()

strlen should give you correct result. Check lpNumberOfBytesWritten, for checking number of bytes written.

Prasad
Notifier using ATL | Operator new[],delete[][^]

Re: Ensure Correct Size

Naveen29-Mar-07 2:31

Naveen

29-Mar-07 2:31

Programm3r wrote:
I have tried strlen()

. Can you paste the code here? Did you check the return value of the strlen function?

nave

Re: Ensure Correct Size

Programm3r29-Mar-07 3:21

Programm3r

29-Mar-07 3:21

Naveen R wrote:
Can you paste the code here?

What do you mean ?

Thanx all I came right.
Regards,

The only programmers that are better than C programmers are those who code in 1's and 0's..... Smile | :)

Programm3r
My Blog: ^_^

Transparent Brush

Md. Mazharul Islam Khan29-Mar-07 0:11

Md. Mazharul Islam Khan

29-Mar-07 0:11

I apply brush over my bitmap image. but i want that brush background will be transparent so that bitmap image can be shown also.

How can i do that?

Cedric Moonen29-Mar-07 1:03

Cedric Moonen

29-Mar-07 1:03

I suppose that you are using a hatched brush (with a solid brush, you cannot make it transparent) ?
If yes, take a look at the SetBkMode[^] function from CDC

Cédric Moonen
Software developer

Charting control [v1.1]

Md. Mazharul Islam Khan29-Mar-07 1:45

Md. Mazharul Islam Khan

29-Mar-07 1:45

Ok, i know about this function.

but how i can apply??

Cedric Moonen29-Mar-07 1:48

Cedric Moonen

29-Mar-07 1:48

mazhar_cse wrote:
but how i can apply??

What do you mean ? Just call the function... What is the problem?

Can you describe more in details your probem ?

Cédric Moonen
Software developer

Charting control [v1.1]

Md. Mazharul Islam Khan29-Mar-07 3:07

Md. Mazharul Islam Khan

29-Mar-07 3:07

The main problem i face that i donot find who call this
"int SetBkMode( int nBkMode )" function??

it returns integer value, but i dont know who use it.

Plz, help me.

prasad_som29-Mar-07 3:15

Using MFC dialogs in a dll [VS2005]

29-Mar-07 3:15

mazhar_cse wrote:
The main problem i face that i donot find who call this
"int SetBkMode( int nBkMode )" function??

Do you missed its documentation[^] ?

Prasad
Notifier using ATL | Operator new[],delete[][^]

benjymous28-Mar-07 23:26

28-Mar-07 23:26

Has the way MFC in dialogs works changed between VC7 and VC8? (or specifically in the latest service pack?)

We've got quite a few DLLs that contain dialogs, that worked fine in VC7 (and we think it was on in the vanilla install of VC8), but now assert then crash inside the dialog's DoModal call:
objcore.cpp line 40

BOOL CObject::IsKindOf(const CRuntimeClass* pClass) const
{
	ENSURE(this != NULL); --- Dies here

Here's the code that opens the dialog

AFX_MANAGE_STATE(AfxGetStaticModuleState()); //needed to display the dialog across the dll

COptionsDlg dlg( CWnd::FromHandle( hwndParent ) );
if( dlg.DoModal() == IDOK )
{
        ...

It seems to work fine in release, but it appears to want to use AfxGetApp() in debug (which returns NULL, and this crashes inside IsKindOf)

We've tried making the DLLs derive from CWinApp, but that seems to fail in the CWinApp constructor when the dll is initialised ( ASSERT(AfxGetThread() == NULL); - I'm guessing the Calling application's thread is being detected here. )

Can anyone help out?

KarstenK29-Mar-07 1:10

KarstenK

29-Mar-07 1:10

It is bad style and MS recommands not to share MFC-Object between different modules.
If you use dlls and exes it is always best to build all with the same VS !!!
Derive dlls from CWinApp.

I think you are in trouble because of these "hacks", and have to redesign your code. Unsure | :~

You better stick with VS2003 to your task, OR redesign for VS2005.

Did you test your code on Vista. (I bet you loose)

SCNR Confused | :confused:

Greetings from Germany

benjymous29-Mar-07 2:58

29-Mar-07 2:58

MFC objects aren't being shared between modules - the child DLL just has its own resources and dialogs (that refuse to open in debug)

For some reason, when I derive my child DLL from CWinApp it's asserting about the AfxThread - presumably its seeing the main app's thread and getting confused.

Sadly going back to 2003 isn't an option, as we have a large codebase, and it's not feasible to have different code built with different versions of visual studio (well, it is, but it'd be a nightmare to maintain!)

KarstenK29-Mar-07 3:11

KarstenK

29-Mar-07 3:11

I googled this one: http://support.microsoft.com/kb/115088/en-us[^]

As ever better do google to search MS-Stuff. Mad | :mad:

Greetings from Germany

benjymous29-Mar-07 3:25

29-Mar-07 3:25

KarstenK wrote:
As ever better do google to search MS-Stuff.

There's no point googling if you don't actually read the resulting pages

MSDN:

If you build an MFC _USRDLL using Visual C++, version 1.0

Believe me, we've been searching for answers and can't find anything relevant.

Why?

_808628-Mar-07 23:16

_8086

28-Mar-07 23:16

int main()
{
static int i=3;
printf("%d",i--);
return i>0 ? main() Blush | :O

;
}

Does this print 321?? Confused | :confused:

----------------------------
286? WOWW! Blush | :O

Rohde28-Mar-07 23:26

Rohde

28-Mar-07 23:26

I've never seen such code before and don't know if it even compiles.

But it uses the conditional operator ( ?: ) in the return statement and continues to call the main method until i has been decremented below 0, and since the main method prints the value of i and the decrements it, the effect is to print 321.

Very bizarre code.

"When you have made evil the means of survival, do not expect men to remain good. Do not expect them to stay moral and lose their lives for the purpose of becoming the fodder of the immoral. Do not expect them to produce, when production is punished and looting rewarded. Do not ask, `Who is destroying the world?' You are."

-Atlas Shrugged, Ayn Rand

benjymous28-Mar-07 23:28

28-Mar-07 23:28

Homework?

There's two things you need to understand here, what static does to that variable declaration, and what the test ? then : else; operation means...

_808629-Mar-07 0:51

_8086

29-Mar-07 0:51

benjymous wrote:
Homework?

No it's a puzzle posted in our intranet.

----------------------------
286? WOWW! Blush | :O

prasad_som28-Mar-07 23:29

28-Mar-07 23:29

_8086 wrote:
Does this print 321??

Yes. Remember i is static.

Prasad
Notifier using ATL | Operator new[],delete[][^]

toxcct28-Mar-07 23:30

toxcct

28-Mar-07 23:30

first of all, when posting code, please use the <pre></pre> tags to keep a well formated message.

then, to understand your result, keep in mind that static variables (declared within a function) stay local to the function (so, not visible from outside) but their lifetime changed to being the program lifetime. that is, a local static variable is initialized at the beginning of the application, and is destroyed when the program exits.
at the first call of the function, the variable as the initialization value. then, each time the function is called, it keeps the last value it had when the function last exited.

int main() {
    static int i=3;
    printf("%d", i--);
    return i>0 ? main():0;
}

1. entering main for the first time:
i == 3
so, 3 is printed (because the i-- decremented the variable only after returning the current value)
i now equals 2
the i>0? main : 0 expression is evaluated. as i is strictly higher than 0, main() calls itself recursively

2. entering main for the second time:
i == 2
printing 2
i == 1 (after decrementation)
i > 0, so re-entering main()

3. entering main for the third time:
i == 1
printing 1
i == 0 (after decrementation)
i not > 0, so returning 0

for all the previous calls to main, the expression returns 0 either, until exiting...

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Eytukan29-Mar-07 1:34

Eytukan

29-Mar-07 1:34

You are hot today! Big Grin | :-D

Press: 1500 to 2,200 messages in just 6 days? How's that possible sir?
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