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#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
The second line aliases the keyword new to DEBUG_NEW, which is itself a macro defined in the Microsoft-specific header afx.h. DEBUG_NEW references THIS_FILE and __LINE__, thereby capturing the faux new's source context for possible tracing and debugging.
----
Can any one pls. explain the purpose of undef in the code above.
This code is almost present in almost in every file, in debug version after debug new is defined, THIS_FILE is used in debugging only then undef is un-defining it then what is the purpose of THIS_FILE.
Rgds,
Arun.
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#undef simply says to the preprocessor that the THIS_FILE macro is not defined anymore after this point of reading...
the same question was asked yesterday... see this[^]
TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VCalc 3.0 soon...]
-- modified at 5:13 Thursday 16th February, 2006
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Yes, I have seen that but couldn't understand that.
Infact this code or the pre-processor directive is excuted in the beginning of the file, if we undef THIS_FILE and defining it again what might have been the value before and now for debugging purposes it's changed to be __FILE__.
can you pls. elaborate what is the value before undefining it.
Rgds,
Arun.
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arunperi wrote: what is the value before undefining it
why do you need to know that ?
i don't know !!
maybe defined without value...
#define THIS_FILE
look in your headers to find the correct definition...
even MSDN[^] don't say much...
TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VCalc 3.0 soon...]
-- modified at 5:36 Thursday 16th February, 2006
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Thank you,
just trying to figure out what could be the purpose of that statement
Rgds,
Arun.
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it's there to prevent the compiler from complaining about multiply-defined macros, in case something else in the #include chain has defined something with that same name.
Cleek | Image Toolkits | Thumbnail maker
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hy everybody,
i really have a strange problem, and i hope that this very nice forum can help me out another time.
So what i have is a very simple com dll, if followed this article to build it: COM-DLL
my prroblem is, when e have a function like this:
[id(5), helpstring("method test2")] HRESULT test2([out,retval] BSTR* str);
i want to return more Parameters with the [out,retval], not only a BSTR* maybe a sequence or an array would be nice! In my Project i have to return 20 Strings to the Client who is using this dll, how does this work?
maybe something like this:
[id(5), helpstring("method test2")] HRESULT test2([out,retval] BSTR* str[20]);
I dont know or passing a sequence or an struct as a return Parameter?
Or what about this VARIANT* Types how does this work?
[id(5), helpstring("method test2")] HRESULT test2([out,retval] VARIANT* );
Please could someone explain it to me, i really need this asap...
Really, thank you in advance,
greetz
Balu
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Since only one parameter (the last one) can be a retval parameter, you can only return one item - but this item can be a array of objects (SAFEARRAY packaged in a VARIANT, perhaps?).
You can try a retval of a VARIANT parameter and build a SAFEARRAY into it. Check the MSDN example for SafeArrayCreateEx(...), it provides an example of creating a SAFEARRAY and putting it into a VARIANT.
Peace!
-=- James
If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
DeleteFXPFiles & CheckFavorites (Please rate this post!)
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Sorry i cant unterstand this mapping of an safearray to variant, i rather dont know where to put that code? Must be in the idl file, because the interface have to know it!?
But i really dont know how to do that!
If someone has an example on how to implement a safe array as a retval of a COM function defined in an idl file!
Or another solution for the problem from the first thread!
greetz
Balu
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My IDL is rusty, so this may not be exactly right, but I think the parameter would be something like:
[out,retval] SAFEARRAY(BSTR)** str_array
SAFEARRAY is a IDispatch-compatible parameter so there's no need to put it in a VARIANT.
--Mike--
Visual C++ MVP 
LINKS~! Ericahist | NEW!! PimpFish | CP SearchBar v3.0 | C++ Forum FAQ
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I am hosting an MSHTML browser control in my app via CHtmlView. Is it possible to get notified as it tries to download each page element (e.g. an image) and force it to instead get it from somewhere else?
It'd be nice if I could also intercept and replace the entire page itself. Right now, I'm doing this in OnBeforeNavigate2() by setting the cancel flag, calling Stop() and then calling Navigate() for the new URL 
The two most common elements in the universe are Hydrogen and stupidity. - Harlan Ellison
Awasu 2.2 [^]: A free RSS/Atom feed reader with support for Code Project.
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Hello,
one of our Networkers asked me, if MFC uses
the Internet Explorer SSL certificates?
I didn't found informations in the internet.
He told me that Java uses own certificates,
so he wanted to know.
Hope someone can help me
Thanx
Dannydust
P.S.: Greetings from Germany 
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I found the Answer!
The SOAP toolkit uses the same certificates as the IE.
Greetings
Dannydust
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I want to communicate with USB port without using RS232 converter in VC/VB.
Please Help
Rujuta
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And to which device is it connected ? There should be a driver supplied with the device and you have to open this driver (with CreateFile) and then send commands using DeviceIOControl. The commands are supplier specific.
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Hi,
I am working on Threading and am using CSingleLock to control access to shared resource. I have a doubt..must the CCritical section be member of the class or can it be local to the function?
1)
void foo()
{
CCriticalSection CritSection;
CSingleLock singleLock(&CritSection);
}
void foo1()
{
CCriticalSection CritSection;
CSingleLock singleLock(&CritSection);
}
2)
CCriticalSection m_CritSection;
void foo()
{
CSingleLock singleLock(&m_CritSection);
}void foo1()
{
CSingleLock singleLock(&m_CritSection);
}
Are both the baove approaches correct?
Please give me your inputs on this?
Thanks
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AFAIK, example 2 is correct.
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The CCriticalSection object must be a member of the class. Both locks must operate on the same object.
Ryan "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"
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Hello
I am developing a dialog based application in which during some processing by application, a dialog box with message "Please wait... while processing." is displayed. For this perpose, I initiate a thread in which processing is done. I used DoModal() to display above dialog in that thread. I want to close it and return to parent window on end of processing. Please tell me how can i do that.
Thank you.
We Believe in Excellence
-- modified at 2:18 Thursday 16th February, 2006
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You know that DoModal is a blocking call ? The function will return only when the dialog is closed. So, if your processing is just afte that, there will be a problem because the processing will be started only when you close your dialog. Take a look at modeless dialogs, I think this will solve your problem. (Then when the processing is finish, you can destroy the modeless dialog).
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Calling DoModal() from your worker thread probably won't work, and even if you do set up a message queue for the thread, showing the dialog on that thread defeats the purpose of having a worker thread.
The main thread should show the dialog. In OnInitDialog(), start the worker thread and pass it the dialog's HWND. When the thread's work is done, post a message (such as WM_APP) to the dialog so it knows the thread's done and it can close itself.
--Mike--
Visual C++ MVP
LINKS~! Ericahist | NEW!! PimpFish | CP SearchBar v3.0 | C++ Forum FAQ
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Probably the simplest way would be to run the routine that does your processing within the dialog box that says "Please wait......" After completion, the routine can close the dialog box (CDialog::OnOK () would do the job). This would also enable you to give the dialog a button that may interrupt the processing (set a flag on pressing that button that you check in your proces's loop). Also, it would be easy to add a progress bar in your dialog box.
If you need a lot of variables from your parent dialog, you can simply pass a pointer to the parent to you modal dialog.
Success.
William
-- modified at 11:41 Thursday 16th February, 2006
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You can try to begin another thread to show the message dialog. in this thread , call DoModal can implement it.
when you begin some job in the main thread, you begin the thread to show the message dialog. after you complete job in the main thread, you can kill the thread for show message dialog.
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Hi,After I created my DLL using ATL. I call it by:
#import and CoCreateInstance
but when I use this dll in another windows (that hasn't Visual Studio)
I gives me Send Don't Send error message.
Please help me,
Thanks.
Every new thing you learn,Gives you a new personality.
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Maybe you should register the dll you created on another windows before you use it.
the command line is: regsvr32 (your dll name)
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