C / C++ / MFC

Steve Echols5-Jul-07 10:04

Steve Echols

5-Jul-07 10:04

class FastCar : public Car
{
public:
   virtual ~FastCar() { delete itsTurbo; }

private:
   Turbo* itsTurbo;
}

FastCar* ferrari = new FastCar();
Car* car = ferrari;
delete car;

I think without the virtual destructor, FastCar's destructor would never get called if it's deleted using a pointer to a base class.

- S
50 cups of coffee and you know it's on!

mid=57416-Jul-07 1:40

mid=5741

6-Jul-07 1:40

Car should have the virtual destructor. It doesn't matter if FastCar has one or not, unless you plan to extend that too.

Steve Echols6-Jul-07 1:59

Steve Echols

6-Jul-07 1:59

True, but I was planning on writing a ReallyFastCar! Smile | :)

- S
50 cups of coffee and you know it's on!

David Crow5-Jul-07 10:13

5-Jul-07 10:13

tom groezer wrote:
Why is the destructor virtual here?

To ensure that the destructor from the most derived class will always be called.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Cyrilix5-Jul-07 12:25

Cyrilix

5-Jul-07 12:25

Wouldn't it be better to do a search first?

Now, asking questions and such is perfectly fine, but I see 5 of your questions on the first page, and this one in particular, is a rather common topic.

tom groezer5-Jul-07 20:02

5-Jul-07 20:02

Basically my question was whether virtual destructors could be used even if you do not have virtual functions in base classes. In the example that I have put I have not put any of the virtual functions.

mid=57416-Jul-07 1:34

mid=5741

6-Jul-07 1:34

The rule of thumb is that classes designed to be base classes that are used polymorphically should have virtual destructors. Classes such as yours without any virtual functions do not require a virtual destructor. Using a virtual destructor in this case wastes some bytes.

David Crow6-Jul-07 2:41

6-Jul-07 2:41

tom groezer wrote:
Basically my question was whether virtual destructors could be used even if you do not have virtual functions in base classes.

That's all well and good, but you asked the same question here.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Reading text

tom groezer5-Jul-07 9:32

5-Jul-07 9:32

How to get the text from the edit box of another application

David Crow5-Jul-07 10:15

5-Jul-07 10:15

Send it a WM_GETTEXT message.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

sheshidar5-Jul-07 23:20

sheshidar

5-Jul-07 23:20

Hi thx,
Can u expalin a bit more how to use this

Hamid_RT6-Jul-07 1:05

Hamid_RT

6-Jul-07 1:05

You need to a handle to that window.

WhiteSky

David Crow6-Jul-07 2:39

HeapWalk and PROCESS_HEAP_ENTRY_MOVEABLE

6-Jul-07 2:39

Knowing how to handle messages (both sending and receiving) is paramount in understanding the very basics of Windows development.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Blake Miller5-Jul-07 7:52

Blake Miller

5-Jul-07 7:52

Has anyone ever seen the PROCESS_HEAP_ENTRY_MOVEABLE bit set in any of the heap entries encountered while walking a heap?

I have allocated some memory using GlobalAlloc(GMEM_MOVEABLE, nBlockSize);
where nBlockSize = 65 * 1024.

When I call HeapWalk and iteratively obtain the PROCESS_HEAP_ENTRY data, I never see the PROCESS_HEAP_ENTRY_MOVEABLE bit set in any of the heap entries.

I used GetProcessHeaps and separately walked each of the 3 heaps my test program has in it.

The entire reason this is an issue is that a process is only allowed 65535 GMEM_MOVEABLE allocations at one time (according to a couple Microsoft documents), and our product is reaching this limit. I want to periodically check, for QA purposes, how many handles have already been used.

how to develop themes

pritthi5-Jul-07 7:22

pritthi

5-Jul-07 7:22

how can I create or develop a theme like the popular themes "crystal xp" or like something else by using Visual C++ / MFC ?

WAITING eagerly for anykind of answers.Thanks in advance.

David Crow5-Jul-07 7:32

5-Jul-07 7:32

Does this help?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

led mike5-Jul-07 8:14

led mike

5-Jul-07 8:14

Would you please stop searching the internet, there is nothing of value there Big Grin | :-D

Perspx5-Jul-07 18:42

Perspx

5-Jul-07 18:42

If you want to do it programmatically, if you have heard of the application WindowBlinds (which skins windows), I believe that it works by injecting a DLL/multiple DLLs into every running application (including explorer.exe to skin the taskbar and start menu), which then takes over the window's window procedure, and custom draws all of the controls.. I'm not sure how much time you want to spend over your appication or how complicated you want it to be.. but I think this is probably the right way to go if you wish to do it programatically..

Hope this helps!
--PerspX

"Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." - Bill Gates

Hamid_RT6-Jul-07 1:06

Hamid_RT

6-Jul-07 1:06

Does this[^] article helpful?

WhiteSky

Windbg

tom groezer5-Jul-07 5:20

5-Jul-07 5:20

Can somebody let me know some good links to windbg tutorials.

David Crow5-Jul-07 7:05

5-Jul-07 7:05

Have you seen this?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

tom groezer5-Jul-07 7:28

5-Jul-07 7:28

I know that link and is used for downloading the debugging framework.

David Crow5-Jul-07 7:35

5-Jul-07 7:35

So have you seen this, or this?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne