C / C++ / MFC

Re: memcpy() not working ?

28-Mar-05 9:26

Amarelia wrote:
Here it doesn't coping the data...

How are you verifying this?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Amarelia28-Mar-05 19:24

Amarelia

28-Mar-05 19:24

I m veryfing by printing data of structure after copying...i.e Usr.a, Usr.b, Usr.str...etc...and it gives nothing....

Is there any other function to copy data from one structure to another structure..?

Thankx for your previous reply.

Mahesh

Amarelia Maehsh
Gujarat
India

Re: memcpy() not working ?

David Crow29-Mar-05 3:12

Problems with HHOOK variable

29-Mar-05 3:12

Is it possible that you are battling a race condition by viewing the contents of the structure before it has had a chance to be copied? Try your same structure-copying code in a single-threaded application and note the results. Hopefully that'll let you know if it is a thread-related issue or not.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

r3dqu33n28-Mar-05 7:08

r3dqu33n

28-Mar-05 7:08

Hello everybody:

I have a problem when compile a program with creates a thread specific hooh

I try to save the value of SetWindowsHookEx into a HHOOK var type
but when i compile the code the compiler gives me an error...
The error says:

error LNK2001: Unresolved external symbol" public: static HHOOK hhookMyHook

i'm making a class with the declaration of the HHOOK variable, it's of public type and i'm calling it from a function into the class

Why is happens????

David Crow28-Mar-05 9:35

28-Mar-05 9:35

You've not provided enough information so my answer is merely a guess.

HHOOK hHook;
...
LRESULT CALLBACK MouseProc( int nCode, WPARAM wParam, LPARAM lParam )
{
    return CallNextHookEx(hHook, nCode, wParam, lParam);
}
...
hHook = SetWindowsHookEx(WH_MOUSE, MouseProc, NULL, 0);

How does yours differ?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

r3dqu33n28-Mar-05 9:45

r3dqu33n

28-Mar-05 9:45

Excuse me, i forgot the rest of the explain...

my code differs in what all these declaration are into a class and the HHOOK is static type...
all of these are public type...

David Crow28-Mar-05 9:51

28-Mar-05 9:51

Savior999 wrote:
my code differs in what all these declaration are into a class and the HHOOK is static type...
all of these are public type...

Makes no difference:

class MyClass
{
public:
    static HHOOK hHook;
    
    static LRESULT CALLBACK MouseProc( int nCode, WPARAM wParam, LPARAM lParam )
    {    
        return CallNextHookEx(hHook, nCode, wParam, lParam);
    }
 
    MyClass()
    {
        hHook = SetWindowsHookEx(WH_MOUSE, MouseProc, NULL, 0);
    }
};

BTW, public and static are mutually exclusive identifiers.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

r3dqu33n28-Mar-05 10:03

r3dqu33n

28-Mar-05 10:03

the problem i what when i try to implement the body of the declaration into the class the compiler raise the mentioned error

may by i don't know how call the variable

class myClass{
static HHOOK myHook;
static LRESULT CALLBACK MouseProc(int nCode, WPARAM wParam, LPARAM lParam);
myClass();
};

static LRESULT CALLBACK myClass::MouseProc(int nCode, WPARAM wParam, LPARAM lParam){
return CallNextHookEx(myClass::hHook, nCode, wParam, lParam);
};
myClass::myClass(){
myClass::hHook = SetWindowsHookEx(WH_MOUSE, myClass::MouseProc, NULL, 0);
}

this is an example code of what i have...

David Crow28-Mar-05 10:22

Re: Bitmap Data Manipulation

28-Mar-05 10:22

To initialize static members from outside of the class declaration requires a slight change. See here for details.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Bitmap Data Manipulation

LighthouseJ28-Mar-05 7:07

LighthouseJ

28-Mar-05 7:07

I found this page to display a bitmap and it works fine, but I need to replace each pixel value from a decompression routine done elsewhere in my app. In the broadstrokes, I'll open a bitmap image, send the bitmap data to be compressed, it'll be decompressed locally, then display the result. I can send the data fine and the decompression is no problem, but I need to display the decompressed result. I'm thinking I can open the image to fill the bitmap structure with the data it needs, then just drop in my decompressed data, then continue with the second half of the code to display the image. I can't seem to find any pages anywhere about this specifically because most projects only display images or maybe even change the palette values, but nothing as specific as what I'm trying to do. I tried to look at where the bitmap data is stored, then just allocate a chunk of memory the same size and just point to my new decompressed data rather than the data from the file but I couldn't locate that. Any help would be appreciated, thanks in advance, Nate.

C^hris L^osinger28-Mar-05 10:42

C^hris L^osinger

28-Mar-05 10:42

the easiest way is to use something like StretchDIBIts.

you'll need to allocate enough memory for your pixels, with each row padded to a multiple of four bytes. then drop your pixels into the rows (in top-down order) - pixels arranged in Blue, Green, Red order. then fill out a BITMAPINFOHEADER structure and hand that to StretchDIBits. this is essentially making a DIB from your pixel data (though a true DIB would have the BMIH struct and pixels in a single buffer). and if you can do that, you're a BITMAPFILEHEADER away from a .BMP file.

well, actually, the easiest way is to run through your pixels and call SetPixel for each, but that's really slow.

Image Toolkits | Image Processing | Cleek

Re: Bitmap Data Manipulation

LighthouseJ28-Mar-05 12:23

LighthouseJ

28-Mar-05 12:23

I'll only be dealing with 8-bit bitmaps. I already wrote the routines to open a bitmap file and read in all the data (2 headers and palette data) myself because I needed to access the actual bytes and that works fine. I figure I can just take those 2 filled out headers I made and hand it to StretchDIB like you mentioned.

error - edit box variable cannot be evaluated

theFrenchHornet28-Mar-05 5:22

theFrenchHornet

28-Mar-05 5:22

I am getting a runtime error that an edit box variable on a dialog cannot be evaluated.
I am not seeing what the problem is and would appreciate it if someone can point it out to me.

There is a global variable declared as:

<br />
double currentBP;<br />

In the first initDialog of the program, currentBP is initialized.

Class CGetNewBP displays a dialog. There is an edit box for the user to enter a value. It is declared as:

<br />
double m_newBP;<br />

When the user clicks OK on this dialog, the value entered into the edit box is transferred to the global currentBP.

On another dialog, there is a button - Change BP. When this button is clicked, the
CGetNewBP dialog is displayed as modal. On return, the global currentBP which was just
updated is assigned to an edit box declared:

<br />
double m_currentBP;<br />

At this assignment, however, an exception is raised saying that m_currentBP cannot be
evaluated. If I comment out the call to create and display CGetNewBP, the code executes
without exception, and m_currentBP displays the initialized value of the global currentBP.
When the display CGetNewBP code is in, and execution is broken at the assignment statement,
the value in the global currentBP has been updated correctly.

<br />
void CModeCtrlDlg::OnBnClickedChangeBP ()<br />
{<br />
  CGetNewBP getNewBP = new CGetNewBP;<br />
  INT_PTR nResponse = getNewBP.DoModal();<br />
  delete getNewBP;<br />
  m_currentBP = currentBP;  <- error message that m_currentBP cannot be evaluated<br />
  UpdateData(false);<br />
}<br />

Without the first 3 lines, no error message and m_currentBP accepts the assignment
and displays on the screen.

I have tried further qualifying m_currentBP as CModeCtrlDlg::m_currentBP, with no success.

Re: error - edit box variable cannot be evaluated

David Crow28-Mar-05 6:02

Re: error - edit box variable cannot be evaluated

28-Mar-05 6:02

theFrenchHornet wrote:
In the first initDialog of the program...

You have more than one?

theFrenchHornet wrote:
There is an edit box for the user to enter a value. It is declared as:

double m_newBP;

The variable associated with the edit control should be CEdit.

theFrenchHornet wrote:
void CModeCtrlDlg::OnBnClickedChangeBP ()
{
CGetNewBP getNewBP = new CGetNewBP;
INT_PTR nResponse = getNewBP.DoModal();
delete getNewBP;
m_currentBP = currentBP; <- error message that m_currentBP cannot be evaluated
UpdateData(false);
}

Several things wrong here. First, don't use a heap-based variable unnecessarily. Second, UpdateData() is also unnecessary. Third, too many variable involved. Fourth, getNewBP is not a pointer so the new operator cannot be used. Try something like this instead:

class CGetNewBP : public CDialog
{
public:
    CEdit m_edit;
    double m_BP; // you could also make this a CString and do the atof()
                 // conversion in the OnBnClickedChangeBP() method
};

void CGetNewBP::OnOK()
{
    CString str;
    
    m_edit.GetWindowText(str);
    m_BP = atof(str);
}
...
class CModeCtrlDlg : public CDialog
{
public:
    CEdit m_editBP;
};
...
void CModeCtrlDlg::OnBnClickedChangeBP()
{
    CGetNewBP dlg;
    INT_PTR nResponse = dlg.DoModal();
    if (IDOK == nResponse)
    {
        CString str;
 
        str.Format("%f", dlg.m_BP);
        m_editBP.SetWindowText(str);
    }
}

Make sense?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

theFrenchHornet28-Mar-05 6:35

theFrenchHornet

28-Mar-05 6:35

Yes - makes sense.

Thanks so much for the quick reply - big help - I learned - have implemented and works.

topmost window stye without getting the focus

Cris28-Mar-05 3:40

Cris

28-Mar-05 3:40

Hello,
I am trying to solve this problem many time ago, but yet no solution: how can i show a window (dialog from CDialog) with the topmost style (showing for the user) but without the focus?

Thanks,
Cris.

Re: topmost window stye without getting the focus

ThatsAlok28-Mar-05 17:47

ThatsAlok

28-Mar-05 17:47

Return FALSE instead in TRUE from CDialog::onInitDialog()in conjunction with SetWindowPos(..) api!

[Vote One Here, Complete my Survey....]

Alok Gupta
visit me at http://www.thisisalok.tk

"I ~~Think~~ Believe this Will Help"

Re: topmost window stye without getting the focus

Cris29-Mar-05 8:10

Cris

29-Mar-05 8:10

Ok, thanks...

MPEG-2 Transport Stream converter

Alexander ^M.,28-Mar-05 3:15

Alexander ^M.,

28-Mar-05 3:15

Hi guys,
I have a MPEG-2 transport stream with 2 pids (1 video, 1 audio) and I am looking for a way to convert it to a MPEG-2 program stream. I've been searching the internet for some time but most things I found were broken links. Does anyone know a good source for information?

Thanks for adivce,
Alex

Don't try it, just do it! Wink | ;-)

problem with DLL and CString

eli1502197928-Mar-05 3:06

eli15021979

28-Mar-05 3:06

Hi,

I need to use a CString object in my dll,so i've included <afx.h> file.
the problem is that i get this error:

Compiling...
TCPlib.cpp
c:\program files\microsoft visual studio\vc98\mfc\include\afxv_w32.h(14) : fatal error C1189: #error :  WINDOWS.H already included.  MFC apps must not #include <windows.h>
Error executing cl.exe.

when i don't include <afx.h> i don't get this error,but i can't use CString.

what should i do?

Regards,
Eli

Joel Holdsworth28-Mar-05 3:39

Joel Holdsworth

28-Mar-05 3:39

1. Ensure thatm you're not including windows.h anywhere in you're dll
2. ensure you have a precompiled header - e.g. stdafx.h
3. add #include <afxwin.h> to stdafx.h
4. make sure you're project settings are set to include MFC

Joel Holdsworth

Wanna give me a job this summer?
Check out my online CV and project history[^]

Alexander ^M.,28-Mar-05 3:41

Alexander ^M.,

28-Mar-05 3:41

When you include a MFC header file you must not include windows.h.
MFC does include it!!
Furthermore you should better not use parts of MFC in an non-MFC application.

Don't try it, just do it! Wink | ;-)

eli1502197928-Mar-05 3:58

eli15021979

28-Mar-05 3:58

Thanks for you prompt reply.
I need to make a regular dll with objects of MFC(i.e CString).
Which DLL workspace should i choose in the MSDEV?

regards,
Eli

Blake Miller28-Mar-05 4:39

Blake Miller

28-Mar-05 4:39

If the program that will load the DLL might NOT be MFC, then choose MFC AppWizard (dll) as the project type. Then in Step 1 of the wizard, make sure you choose "Regular DLL with MFC statically linked". This will allow your DLL to use MFC but the parent application does not have to be an MFC program. Don't pass MFC objects between your DLL and your program, or you might experience memory issues and the created MFC objects are not necessarily from the same memory pools.