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You need to define the static member pointer. Write the following statement in the source (*.cpp) file
classA * classA::a = NULL;
BTW you missed a semicolon at the end of the class declaration.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
[my articles]
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Thank you for the quick response. It works now.
I have been doing some research in the meantime.
I am not sure if I understand why I have to do this extra reference.
Is it because static limits the visibility of the variable to the include <.h> file?
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jupiter1000 wrote: I am not sure if I understand why I have to do this extra reference.
Is it because static limits the visibility of the variable to the include <.h> file?
According to MSDN [^]
Static data members are not part of objects of a given class type; they are separate objects. As a result, the declaration of a static data member is not considered a definition. The data member is declared in class scope, but definition is performed at file scope. These static members have external linkage
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
[my articles]
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Hey, I use my printer dc to paint some text and graphic to my printer. I use MM_LOMETRIC as Mapmode because of the easy way of positioning. Now I have a big problem to print bitmaps. All bitmaps are mirrowed (around X-axis).
I use the following code to paint the bitmap:
<br />
<br />
<br />
....<br />
CBitmap *pBitmap = new CBitmap();<br />
HBITMAP hBitmap;<br />
hBitmap = (HBITMAP)::LoadImage(AfxGetInstanceHandle(),szPathToBitmap,IMAGE_BITMAP,0,0,LR_LOADFROMFILE|LR_CREATEDIBSECTION);<br />
pBitmap->Attach(hBitmap);<br />
...<br />
<br />
<br />
<br />
CRect reRect;<br />
<br />
reRect.left = 10;<br />
reRect.right = 300;<br />
reRect.top = -100;<br />
reRect.bottom = -1000;<br />
<br />
CDC dcMem;<br />
BITMAP bm;<br />
<br />
pBitmap->GetBitmap(&bm);<br />
dcMem.CreateCompatibleDC(pDC);<br />
dcMem.SelectObject(pBitmap);<br />
pDC->BitBlt(reRect.left, reRect.top, bm.bmWidth, bm.bmHeight, &dcMem,0,0, SRCCOPY);<br />
<br />
<br />
What's wrong, and how could I fix it?
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Maybe try
pDC->StretchBlt(reRect.left, reRect.top, bm.bmWidth, -bm.bmHeight, &dcMem, 0, 0, bm.bmWidth, bm.bmHeight, SRCCOPY);
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.freetls.fastly.net/script/Forums/Images/coffee.gif)
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Thanks, this works fine for me (only the position is shifted), but why is the bitmap mirrored?
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AnTri wrote: but why is the bitmap mirrored?
The Y-axis is flipped by MM_LOMETRIC and BitBlt() renders
scanlines in the positive direction from the starting point.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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Hello everyone,
Should I delete memory pointed by pointer a if there is bad_alloc when allocating memory in memory pointed by pointer b? I am not sure whether there will be memory leak if I do not delete a.
try {
a = new int [N];
b = new int [M];
} catch (bad_alloc)
{
}
thanks in advance,
George
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You have always to do your cleanup stuff!
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
[my articles]
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Thanks CPallini!
I think you mean we have to delete A, right?
regards,
George
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Yes.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
[my articles]
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Thanks for your confirmation, CPallini!
regards,
George
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But I suggest he should do something like this :
<br />
if(pMyStuff!=NULL)<br />
{<br />
delete pMyStuff;<br />
}<br />
OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus
Best wishes to Rexx[^]
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And you are right!
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
[my articles]
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Hello George, nice to see you again. But this time I've got a question for you. Straight to you. Why do are you acting 'quick'-judgemental before someone could actually reply you fully?
See here[^]
And I've seen many times , anybody who replies to your thread gets a 3 vote. Immediately. Is it a token of acknowledgment to say that you've read the message? . I'm really not hurt by that but I'm finding it funny! Why do you do that?
OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus
Best wishes to Rexx[^]
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In a case like this you should initialize both a and b to 0 before the try clause. You cannot delete a or b at this stage, I assume you will need to use them later, or what was the purpose of allocating them?
int* a = NULL;
int* b = NULL;
try {
a = new int [N];
b = new int [M];
} catch (bad_alloc)
{
// Tell the user if a or b failed...
}
// Do some stuff on a or b
// Now delete if they are allocated
if(a)
delete a[];
if (b)
delete b[];
Thanks!
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Thanks pierre_ribery,
I want to confirm with you that your point is we need to delete a or b if they are successful allocated, even if bad_alloc happens (may be caused by other statements), right?
regards,
George
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Yes that was exactly my point!
If you have allocated memory, then you have to delete it. Therefore it is vital to initialize your pointers to 0 before using them.
Cheers,
Pierre
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Thanks for your advice, Pierre!
regards,
George
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Why you didnt use like this code
try
{
int * a= new int[N];
int * b= new int[M];
}
catch (bad_alloc&)
{
cout <<"Error allocating memory!";
}
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huh Hamid! 
it's simply because he should have put it like:
int* a;
int* b;
try
{
a= new int[N];
b= new int[M];
}
catch (bad_alloc&)
{
cout <<"Error allocating memory!";
}
wake up!
OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus
Best wishes to Rexx[^]
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Yeah it was a quick sample. 
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Not like that, see my earlier post.
Always initialize pointers!! In this case set them to NULL(0).
int* a = NULL;
int* b = NULL;
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Who said I didn't do it? I'm a c++ programmer.
class myclass
{
int* a;
int* b;
myclass()
{
a= NULL;
b= NULL;
}
}
OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus
Best wishes to Rexx[^]
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Your code said it.
Anyway, I think it is pretty important to show it in the code as well.
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