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Re: Conditional variable declaration

KarstenK14-Jun-07 0:34

14-Jun-07 0:34

Why dont ship the GDI+ stuff? It would be nice for your kings (costumers) Cool | :cool:

Cool | :cool:

I do such stuff via a global pointer which has 0 as start value.

CMyCtrl *gpCtrl = 0;

if( IsGdiPlus() )
{
gpCtrl = new CMyCtrl;
}

....

if( gpCtrl )
{
gpCtrl->Show();
}

Greetings from Germany

Re: Conditional variable declaration

Naveen14-Jun-07 0:41

14-Jun-07 0:41

GetVersionEx() will return the current verion of the OS.

nave

[OpenedFileFinder]

Re: Conditional variable declaration

Hans Dietrich14-Jun-07 0:44

14-Jun-07 0:44

Try delay loading GDI+ - see here.

Best wishes,
Hans

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Re: Conditional variable declaration

James R. Twine14-Jun-07 1:52

James R. Twine

14-Jun-07 1:52

   If you want to run on both GDI+ and non-GDI+ systems, you will either have to write two sets of drawing code (one old GDI or DirectDraw, the other GDI+, possibly abstracting the difference into classes), and no longer implicitly link with the GDI+ library. You would have to explicitly look for the GDI+ DLL and if found, load its API from the DLL using GetProcAddress(...), or use the old GDI code if not, but this is harder than it might first seem due to how GDI+ has a C++ class-like interface.

   FWIW, I believe that like others here, including the merge module in your installer for GDI+ is the best idea. It provides the easiest way to get your app to work on the most platforms with the least amount of work. This is no different than requiring an updated ODBC driver or service pack level.

   Peace!

-=- James
Please rate this message - let me know if I helped or not!<HR>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!
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ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 0:18

14-Jun-07 0:18

I have a dialog based project.
The program would crash after just a short moment(no longer than 1 min).
There had an assert at the 895th line of "wincore.cpp":

#ifdebug
CWnd::AssertValid()const
{
...
...
line 892: ASSERT( (p = pMap->LookupPermanent(m_hWnd)) != NULL ||(p = pMap->LookupTemporary(m_hWnd)) ! = NULL);
.......
}

Why?
And how to resolve it?
Thanks.

GOOD LUCK

Re: ASSERT()! Why?And how to resolve it?

Naveen14-Jun-07 0:31

14-Jun-07 0:31

run the application in the debug mode. when the Assert dialog appeares click on the retry button. the it will show the above line in the wincore.cpp. Take the call stack at this momment and look from which part of your code this function gets called.

nave

[OpenedFileFinder]

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 1:04

14-Jun-07 1:04

yes,I did know where the assert occured.
But it in the member function CWnd::AssertAvlid() function.
It was not in my class 's member function.

So,follow your way,how to find witch code of mine bring up such an assert?

Thanks

Re: ASSERT()! Why?And how to resolve it?

Naveen14-Jun-07 1:12

14-Jun-07 1:12

This information can be retrived from the call stack window and also from the variale window.

When you have pressed the rety button the application will be breaked. At that time take the variable window. On the top of that window you can find a combobox called "Context". Drop it. Check whether there is any of your function listed in it. Suppose there are three function say f1(), f2() and f3(), If f1 calls f2 and then f2 calls f3, the f3 calls the above funtion of CWnd, the comboboc will look like

cwd::functionname()
f3()
f2()
f1()

nave

[OpenedFileFinder]

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 19:59

14-Jun-07 19:59

I would have a try and if there would be some other questions I hope I can gain hands from here.
Thanks.

Re: ASSERT()! Why?And how to resolve it?

Naveen14-Jun-07 20:06

14-Jun-07 20:06

kcynic wrote:
I hope I can gain hands from here

Sure.

nave

[OpenedFileFinder]

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 21:35

14-Jun-07 21:35

but I using VS2005 to debug it.How should I doing such things?

Re: ASSERT()! Why?And how to resolve it?

_AnsHUMAN_ 14-Jun-07 0:33

14-Jun-07 0:33

You may be using an unassigned variable or deleting a pointer that does not exist or doing some other incorrect operation. It should ideally not be the MFC files that would show an Assertion error.
Did you try and debug your code?

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

Wink | ;-)

_AnShUmAn_

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 1:06

14-Jun-07 1:06

but I did nothing when the dilog disapeared.
It would crash after about one min!

Re: ASSERT()! Why?And how to resolve it?

22491714-Jun-07 0:34

14-Jun-07 0:34

was this dialog created by a non mfc-thread ?

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 1:00

14-Jun-07 1:00

no,this dialog was create in a function of its parent dialog which also derived from CDialog

Re: ASSERT()! Why?And how to resolve it?

22491714-Jun-07 1:45

14-Jun-07 1:45

are you calling the DoModal() with a NULL from a different thread ?

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 1:57

14-Jun-07 1:57

I only using its member function ShowDialog(TRUE) to make the dialog appeared after I create the modeless dialog.That wat right or wrong to use modeless dialog?
Thanks

Re: ASSERT()! Why?And how to resolve it?

KarstenK14-Jun-07 0:37

14-Jun-07 0:37

the handle is valid that is clear. It means there is something wrong. In most cases the windows has been destroyed or the windows was not properly (created, from another Thread) Dead | X|

Dead | X|

Greetings from Germany

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 1:20

14-Jun-07 1:20

I think there is no window destroyed and no handle is acessed during such process,because no action I had done.

Re: ASSERT()! Why?And how to resolve it?

KarstenK14-Jun-07 1:41

14-Jun-07 1:41

As I see you havent read my posting with the needed correctness. If you have 2 dialogs and share some data, as handles or messaging you HAVE to create them in the SAME thread. Mad | :mad:

Mad | :mad:

Greetings from Germany

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 2:11

14-Jun-07 2:11

I create the second dialog in the function of the first dialog. I also using GetCurrentThreadId() to indicate the thread ID is the same.

Re: ASSERT()! Why?And how to resolve it?

KarstenK14-Jun-07 2:20

14-Jun-07 2:20

That sounds fine.

Can you indentify to which windows the asserting handle belongs? (Tooltip?)
Are you creating others windows in one of the dialogs?

Greetings from Germany

Re: ASSERT()! Why?And how to resolve it?

kcynic14-Jun-07 3:07

14-Jun-07 3:07

No,I only cound found the assertion occured in the wincore.cpp,but nothing .
How should I know witch code I write bring up such problem?

Re: ASSERT()! Why?And how to resolve it?

KarstenK14-Jun-07 3:17

14-Jun-07 3:17

You must step back to find the position or put out all window handles, or look at the call stack. There is also the Spy++ program.

I think the problem is to heavy for your experience, you should ask someone to debug your code. A collegue or a friend. SCNR

Greetings from Germany

Re: ASSERT()! Why?And how to resolve it?

Roger Stoltz14-Jun-07 1:04

14-Jun-07 1:04

A few lines down from the position in wincore.cpp you refer to is a comment that says:

// Note: if either of the above asserts fire and you are
// writing a multithreaded application, it is likely that
// you have passed a C++ object from one thread to another
// and have used that object in a way that was not intended.
// (only simple inline wrapper functions should be used)
//
// In general, CWnd objects should be passed by HWND from
// one thread to another.  The receiving thread can wrap
// the HWND with a CWnd object by using CWnd::FromHandle.
//
// It is dangerous to pass C++ objects from one thread to
// another, unless the objects are designed to be used in
// such a manner.

You should read this article[^] the "Thread Maps" section in this article[^].
After you've read those articles you will know what to do and how to pass a MFC window object from one thread to another.

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

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