BOOL and bool - C / C++ / MFC Discussion Boards

CEx25-Sep-03 1:47

25-Sep-03 1:47

I need to implement ICopyHook interface inorder to intercept copy,rename and delete commands. I have basic knowledge of COM, Can anybody give me some guide lines as in how to begin implementing this ??

Please note I am looking for very basic tips, starting from how to create my own interface? is it like adding class ?? if yes whats the procedure ??

any and every help would be much appreaciated.

Thanks

Abhishek Narula

Re: ICopyHook any help ?

Michael Dunn25-Sep-03 4:49

Michael Dunn

25-Sep-03 4:49

See these articles:

The Complete Idiot's Guide to Writing Shell Extensions - Part I[^]

Introduction to COM Part II - Behind the Scenes of a COM Server[^]

--Mike--
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber
CP SearchBar v2.0.2 released

Re: ICopyHook any help ?

CEx26-Sep-03 23:56

CEx

26-Sep-03 23:56

Thanks Mike, just downloaded your articles appears to be exactly what I was looking for .. Thanks the help.

Regards,

Abhishek Narula

Using crystal reports with VC++

Mr Bose Dayala25-Sep-03 1:39

Mr Bose Dayala

25-Sep-03 1:39

We are using the 'Crystal Report Control 4.6' as an OLE component in VC++. While using the SetAction() function provided by the OLE component, we are getting an error "Unable to load Report".

If some one has worked on the same or has any idea how to rectify the error please respond. Thanks

ThomasKennedyBose

VS6 Workspaces and Projects

HeiniBlad25-Sep-03 0:55

HeiniBlad

25-Sep-03 0:55

Hello,

i have problems creating a larger projects.
i want my project to have a directory structure like this

main
+ bin
-+ debug
-+ release
+ source
-+ project1
-+ project2
-+ project3

what is the best way to start this?
how can i reuse these settings for new projects?
all ideas are welcome.

Record Number of Windows

vancouver77725-Sep-03 0:13

vancouver777

25-Sep-03 0:13

I am developinng a MDI application.
Wanna know if there are ways to record how many windows
were open last time when you close an application.
Just like photoshop.

Shin

Re: Record Number of Windows

yfmain25-Sep-03 0:31

yfmain

25-Sep-03 0:31

I am not sure your question.
Do you wanna restore all windows opened last time when you run your application again, or just record the number of windows.

For the latter one, you can write this as a key into your ini file or registry before you destory all your windows.

Nice to learn

yfmain

BOOL and bool

Saurabh_Delhi25-Sep-03 0:12

Saurabh_Delhi

25-Sep-03 0:12

Hi,

Can we use the BOOL and bool interchangebly in a VC++ code.

That means can true and TRUE be used interchangebly?

I have a piece of code, working fine but using false for a BOOL variable.

Regards,
Saurabh

Re: BOOL and bool

RChin25-Sep-03 0:47

RChin

25-Sep-03 0:47

Saurabh_Delhi wrote:
Can we use the BOOL and bool interchangebly in a VC++ code.

Strictly speaking they shouldn't really be.
Look at it as bad programming practice if you
do mix these types (the compiler does warn you!).

I have to admit using these interchangeably in my code, but I have recently
tried not to anymore.

Look at this posting that relates to your question:
http://www.codeproject.com/script/comments/forums.asp?msg=618883&forumid=1647&XtraIDs=1647&searchkw=BOOL+bool&sd=6%2F27%2F2003&ed=9%2F25%2F2003#xx618832xx[^]

This is also a related article by Nish:
http://www.codeproject.com/buglist/virtualboolbug.asp[^]

I Dream of Absolute Zero

Re: BOOL and bool

Dangleberry25-Sep-03 1:12

Dangleberry

25-Sep-03 1:12

I think the Frankie goes to hollywood song "Relax, don't do it" comes to mind.

Re: BOOL and bool

Michael Dunn25-Sep-03 4:52

Michael Dunn

25-Sep-03 4:52

BOOL is a Windows typedef, 4 bytes long. Its values are TRUE and FALSE.
bool is a built-in C++ type, 1 byte long. Its values are true and false.

That's all you need to know. Don't mix them. Sure, if you write:

BOOL b = false;

it will work, but it also looks like you don't know the difference between BOOL and bool. If you write this during an interview, it will reflect unfavorably on you. Wink | ;)

--Mike--
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber
CP SearchBar v2.0.2 released

Re: BOOL and bool

vcplusplus25-Sep-03 5:02

vcplusplus

25-Sep-03 5:02

BOOL
====
typedef int BOOL;

bool From MSDN Library
=======================
In Visual C++4.2, the Standard C++ header files contained a typedef that equated bool with int. In Visual C++ 5.0 and later, bool is implemented as a built-in type with a size of 1 byte. That means that for Visual C++ 4.2, a call of sizeof(bool) yields 4, while in Visual C++ 5.0 and later, the same call yields 1. This can cause memory corruption problems if you have defined structure members of type bool in Visual C++ 4.2 and are mixing object files (OBJ) and/or DLLs built with the 4.2 and 5.0 or later compilers.

fingerprints recognition

jimmy_me24-Sep-03 23:35

jimmy_me

24-Sep-03 23:35

hi
can anybody send me a fingerprints recognition code. in vc++ or any other language. or even tell me where to get tht code.
i'll b very thankful to u ppl

SelectObject?

Zizilamoroso24-Sep-03 23:33

Zizilamoroso

24-Sep-03 23:33

Right now, I'm doing this:

CPaintDC dc(this);<br />
CBrush brush(RGB(255,0,0));<br />
HBRUSH oldbrush=(HBRUSH)dc.SelectObject(&brush);<br />
...<br />
dc.SelectObject(oldbrush);

It works, but there's a HUGH memory leak. Frown | :(

If I remove the SelectObject() lines, there's no leak anymore, so I assume that it's the SelectObject(), or the Brush maybe. But objects are destroyed at the end of the scope, no?

Is there another solution that guarantees complete release of resources?

using: [VISUAL STUDIO 6.0 sp5] [WIN98/2]

Re: SelectObject?

Anonymous24-Sep-03 23:46

Anonymous

24-Sep-03 23:46

Changed to this:
dc.SelectObject(brush);
and the leak is gone.

So, you should pass a copy of the object instead of the pointer to the object. Strange, cause I've seen this code hundreds of times on this site...

I was stuck with this for a couple of days, and you'll always see that the moment you post a question about this, you'll find the solution yourself. Wink | ;)

Sorry about that.

Re: SelectObject?

Steve S25-Sep-03 1:00

Steve S

25-Sep-03 1:00

You could try

dc.SaveDC();

and

dc.RestoreDC(-1);

to save and restore the DC state. That should work.
The brush and any other objects can only be destroyed if they are not being referred to by the DC, so your stuff should work anyway...

Steve S

Re: SelectObject?

Zizilamoroso25-Sep-03 1:37

Zizilamoroso

25-Sep-03 1:37

It works, that's true ... but after 5 seconds you've wasted 512 meg of ram. Frown | :(

Adding dc.SaveDc() and dc.RestoreDC(-1) doesn't make a difference, still leaking.

Passing the brush object instead of the pointer is the only thing that works. But then we are using deep copies (I assume that) and that doesn't speed things up.

using: [VISUAL STUDIO 6.0 sp5] [WIN98/2]

Re: SelectObject?

Steve S25-Sep-03 1:40

Steve S

25-Sep-03 1:40

Your mix of things might be why.

Does

CBrush* pOld = dc.SelectObject(&brush);

...

dc.SelectObject(pOld);

still leak?

Steve S

Re: SelectObject?

Zizilamoroso25-Sep-03 1:55

Zizilamoroso

25-Sep-03 1:55

That results in a crash when selecting a pen instead of a brush (selecting a brush is doing allright).

Strange...

Is it the stockobject?
CPen* oldpen=(CPen*)pDC->SelectObject(GetStockObject(NULL_PEN));

using: [VISUAL STUDIO 6.0 sp5] [WIN98/2]

Re: SelectObject?

Steve S25-Sep-03 2:08

Steve S

25-Sep-03 2:08

Wouldn't it be easier to use pDC->SelectStockObject(NULL_PEN) ?

There are caveats to do with the fact that the pointer may well, in this case be to a temporary CGdiObject, so shouldn't be used in different messages.

I normally use SelectStockObject, or failing that,

CPen* oldpen = (CPen*)pDC->SelectObject(CPen::FromHandle(::GetStockObject(NULL_PEN)));

I prefer use of an explicit FromHandle() call rather than relying on a cast operator.

Steve S

Re: SelectObject?

Zizilamoroso25-Sep-03 3:46

Zizilamoroso

25-Sep-03 3:46

SelectStockObject instead of SelectObject(GetStockObject) does the trick.

tnx.

Re: SelectObject?

Zizilamoroso25-Sep-03 4:03

Zizilamoroso

25-Sep-03 4:03

This eats ram like hell too:

CPen pen(PS_SOLID,1,m_clrForeground);<br />
CPen* oldpen=(CPen*)pDC->SelectObject(&pen);<br />
...<br />
pDC->SelectObject(oldpen);

I don't understand this, it's code I see a lot. I feel kinda stupid...

using: [VISUAL STUDIO 6.0 sp5] [WIN98/2]

Debugger

Rage24-Sep-03 23:26

Rage

24-Sep-03 23:26

Hi CPians!

I'd like to debug my app, which is a C-dll with visual C++ 6.0. It is bound to an application, which is loaded when starting the debugger.

My problem is that the debugger will not stop at the breakpoints ... I made sure that I have opened the corresponding file (I mean the file that actually gets compiled, and not a copy of the project), that my dll is really being loaded by the application (renaming it would crash the app), and that my code gets compiled (I do not get that message you usually get when trying to put a breakpoint on a part of code which is not compiled). Besides, I am really positive that the code has to go through where I put my breakpoints.

So ... I am lost ... any suggestion ?

Thanks

~RaGE();

Re: Debugger

JWood25-Sep-03 6:24

JWood

25-Sep-03 6:24

This can sometimes happen moved your project to a different directory, then editted code in the new directories. Some files are still pointing to the old directory.

J.
----------------------------

MFC Dialog

hph24-Sep-03 23:06

hph

24-Sep-03 23:06

hi,

i have a problem with my MFC Dialog, i want to add a minimized respectively a maximized item into the popupmenu, which appears if the right mouse button is pressed on my dialog in the taskbar! There are only MOVE and EXIT items in it! I don't know how to get them in there!

Can someone help me ?

Thanks in advance!

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