C / C++ / MFC

Trouble passing a class pointer to AfxBeingThread

23-Aug-05 13:14

No, I found the instructions about CMake, but initially I just saw a VS2003 project and expected it to work. Why would they have a broken project file in there, I don't get it ?

Anyhow, I've nearly got it building, if I have more trouble with it, I'll go back to CMake. The reason for this is that this library links into the project that I've moved to VC2005, and I get a lot of basic_ostream linking errors on this library, so I need to be able to compile it to figure out the problem and fix it.

Christian Graus - Microsoft MVP - C++

ClistCtrl question

Tom Wright22-Aug-05 12:54

Tom Wright

22-Aug-05 12:54

I've got a list control that I'm using for different profiles in my app. When I add a profile to the control it lists it correctly. However when I delete a profile I cannot get the control to move up the icons so that they are taking up the space. Is there a way to move the icons up without reloading the list control?

Thanks

Tom Wright
tawright915@yahoo.com

Re: ClistCtrl question

Jose Lamas Rios22-Aug-05 17:02

Jose Lamas Rios

22-Aug-05 17:02

Tom Wright wrote:
Is there a way to move the icons up

I'm not sure if I got your question right, but maybe you are looking for this method:

CListCtrl::Arrange[^]

Or you might use the LVS_AUTOARRANGE style.

--
jlr
http://jlamas.blogspot.com/[^]

Re: ClistCtrl question

Tom Wright23-Aug-05 4:57

Tom Wright

23-Aug-05 4:57

Thanks that did it.

Tom Wright
tawright915@yahoo.com

KnaveR77722-Aug-05 12:49

KnaveR777

22-Aug-05 12:49

Hey all, Im having a problem with passing a var to a function via AfxBeginThread. It appears the function is being called properly, but my data, which is in the form of a pointer to one of my ServerData classes, appears corrupted in the eyes of the thread function (debugger shows data as it should be before call, inside thread function, everything is chaotic).

This is the code the starts the thread (triggered by a CListView message):

<br />
LPVOID ptr = (LPVOID)((ServerData)m_serversList[pNMIA->iItem]); <br />
ServerData* sdat = (ServerData*)ptr;  // debugger shows sdat to be intact<br />
<br />
CWinThread* thread = AfxBeginThread(&queryServer, ptr);<br />

This is performed at the begining of my thread func:

<br />
UINT queryServer(LPVOID pParam ){<br />
ServerData* server = ((ServerData*)pParam);  // the var server has bad data<br />
<br />
...<br />
}<br />

ServerData's LPVOID cast operator is simply defined as:

<br />
return this;<br />

Any ideas?

Re: Trouble passing a class pointer to AfxBeingThread

MailtoGops22-Aug-05 23:00

MailtoGops

22-Aug-05 23:00

Hi KnaveD,

I would like to interpret the following your statement..

LPVOID ptr = (LPVOID)((ServerData)m_serversList[pNMIA->iItem]);

I can assume that m_serversList[pNMIA->iItem] returns the ServerData object from an array of m_serversList. If you look at your typecasting, it seems to be, it is returning a temporary object, which you are typecasting to a void. That object is not at all a pointer!!!!

Solution
---------

If I am not wrong, you can modify your code like this..

LPVOID ptr = (LPVOID)((ServerData*) &m_serversList[pNMIA->iItem]);

ie to get the address of the array element..

" Action without vision is only passing time,
Vision without action is merely day dreaming,
But vision with action can change the world "

- Words from Nelson Mandela

Thanks & Regards,

Gopalakrishnan

Q about WINDBG

valerie9922-Aug-05 12:41

valerie99

22-Aug-05 12:41

Hi, all

I have installed the WINDBG and trying to use it for VC6, my question is how to open up and memory dump in VC6 and attach to the source code? could it be done for VC98?

The reason I am trying this is the release version of application crashed on one testing box with "application error" and not happening on my side.....so I installed the WINDBG in test box and created the memory dump.....

any info will be greatly appreciated.

Re: Q about WINDBG

Blake Miller23-Aug-05 4:28

Blake Miller

23-Aug-05 4:28

You are probably better off to open the memory dump in the WINDBG.
WINDBG makes a 'fuller' memory dump than the VC6 can understand.

If you fill in the WINDBG folders for symbols and source files, it will lead you to exactly the source file and line where the crash occurred, based upon the information in the DMP file.

Open the DMP file first.
Set the 'symbols' path to point to your PDB files that EACTLY match the release build the customer has.
Set the path leading to your source files.
Issue a .reload in the WINDBG command window.
Execute a 'g' command to 'go' and it will lead you to the crash.

How to use the WIN32API in MFC Application??

shanzy22-Aug-05 12:03

22-Aug-05 12:03

BOOL CMyApp::InitInstance()
{
m_pMainWnd = new CMyFrameWnd;
m_pMainWnd->ShowWindow(m_nCmdShow);
m_pMainWnd->UpdateWindow();

return TRUE;
}

I change it to the next code block,but I got some error

BOOL CMyApp::InitInstance()
{
m_pMainWnd = new CMyFrameWnd;
::ShowWindow(hWnd,m_nCmdShow);
::UpdateWindow(hWnd);

return TRUE;
}

Is there any WIN32API can change "m_pMainWnd" to "hWnd"??

shanzy1980

Christian Graus22-Aug-05 12:40

22-Aug-05 12:40

It has a m_hWnd property, from memory. MFC is a wrapper for Win32, so it's all in there.

Christian Graus - Microsoft MVP - C++

shanzy22-Aug-05 12:50

22-Aug-05 12:50

Thank you!

But when I code like this:

::ShowWindow(m_hWnd,SW_SHOWNORMAL);

I got a error: error: identifier "m_hWnd" is undefined

I want to know which WIN32API can change a handle to a pointer to Class??

shanzy1980

Christian Graus22-Aug-05 13:03

22-Aug-05 13:03

I meant m_pMainWnd->m_hWnd, and I said I *think*, I expected you'd use intellisense to work out how close I was.

shanzy1980 wrote:
::ShowWindow(m_hWnd,SW_SHOWNORMAL);

Ah.... If you call ShowWindow without the ::, I think there's a method on the class. Or you can do this:

::ShowWindow(*this, SW_SHOWNORMAL);

because when you deference the point, there's an operator HWND.

shanzy1980 wrote:
I want to know which WIN32API can change a handle to a pointer to Class??

None, that can't work. Win32 came first, so the framework knows about Win32, Win32 does not know about MFC. Win32 is for use in C as well, so it cannot support classes at all.

Christian Graus - Microsoft MVP - C++

shanzy22-Aug-05 14:01

22-Aug-05 14:01

I'm a beginer,and now I read the book《Programming Windows with MF,second Edition》,this is the source code:

//myfirst.h

class CMyApp:public CWinApp
{
public:
virtual BOOL InitInstance();
};

class CMyFrameWnd:public CFrameWnd
{
public:
CMyFrameWnd();
protected:
afx_msg void OnPaint();
DECLARE_MESSAGE_MAP()
};

////////////////////////////////////////////////

#include <afxwin.h>
#include "myfirst.h"

CMyApp theApp;

BOOL CMyApp::InitInstance()
{
m_pMainWnd = new CMyFrameWnd;
::ShowWindow(*this,SW_SHOWNORMAL);
::UpdateWindow(*this);

return TRUE;
}

BEGIN_MESSAGE_MAP(CMyFrameWnd, CFrameWnd)
ON_WM_PAINT()
END_MESSAGE_MAP()

CMyFrameWnd::CMyFrameWnd()
{
Create(NULL, _T("myfirstMFC"));
}

void CMyFrameWnd::OnPaint()
{

CPaintDC mydc(this);

CRect rect;

GetClientRect(&rect);

mydc.DrawText(_T("MFC"),-1,&rect,DT_SINGLELINE|DT_CENTER|DT_VCENTER);
}

It also don't work, If you can explain with circumstances why it doesn't work

Thanks!

shanzy

Christian Graus22-Aug-05 14:03

22-Aug-05 14:03

Well, what do you mean when you say it doesn't work ? Does it have errors ? Does it not do what you're expecting ? I'll try to recreate this project locally and see what I can find, but any info you can give on the difference between what you're seeing and what you're expecting would help me to help you.

Christian Graus - Microsoft MVP - C++

shanzy22-Aug-05 14:08

22-Aug-05 14:08

I got a LINK error:

catastrophic error: #error directive: Please use the /MD switch for _AFXDLL builds
#error Please use the /MD switch for _AFXDLL builds

Christian Graus22-Aug-05 14:10

22-Aug-05 14:10

You're using VC6 Smile | :)

( I worked that out by looking at the code, not the error ). VC6 is kind of crap, but it's OK for learning. When you get to understand C++, you'll want to upgrade.

I'd say this means you have your app running at the same time as the compiler is trying to write to it, that's all. If it's not visibly running, hit CTRL-SHIFT-ESC for the task manager, look through the processes and kill it there.

Christian Graus - Microsoft MVP - C++

shanzy22-Aug-05 14:26

22-Aug-05 14:26

OK,I know it,Thank you very much!!

Jose Lamas Rios22-Aug-05 17:25

Jose Lamas Rios

22-Aug-05 17:25

shanzy1980 wrote:
I change it to the next code block,but I got some error

Why do you want to change it? MFC's CWnd (and derived classes) are wrappers around window handles (those hWnd you see here and there). I can understand that if you obtained an hWnd somehow (e.g.: creating a window yourself using one of the API functions) you may not want to create an MFC CWnd class to wrap it, but if you already have one of the CWnd objects, why would you want to use the API directly instead of using the corresponding class methods?

Anyway... In your code:

BOOL CMyApp::InitInstance()
{
   m_pMainWnd = new CMyFrameWnd;
   ::ShowWindow(hWnd,m_nCmdShow); 
   ::UpdateWindow(hWnd);
 
return TRUE;
}

After m_pMainWnd = new CMyFrameWnd, m_pMainWnd points to a CMyFrameWnd object, but the window won't be still created (unless you added some code to the class constructor to do it).

In ::ShowWindow(hWnd,m_nCmdShow); and the next line, hWnd is undefined.

The translation from CWnd methods to API calls should be like this:

BOOL CMyApp::InitInstance()
{
   m_pMainWnd = new CMyFrameWnd;
   ::ShowWindow(m_pMainWnd->m_hWnd, m_nCmdShow); 
   ::UpdateWindow(m_pMainWnd->m_hWnd);
 
return TRUE;

Hope that helps,

--
jlr
http://jlamas.blogspot.com/[^]

ThatsAlok22-Aug-05 20:13

ThatsAlok

22-Aug-05 20:13

shanzy1980 wrote:

m_pMainWnd = new CMyFrameWnd; ::ShowWindow(hWnd,m_nCmdShow); ::UpdateWindow(hWnd);

In continuation With jose!, here is one more method to achieve same as Mr. Jose stated in his last post!:-

m_pMainWnd = new CMyFrameWnd;
::ShowWindow(m_pMainWnd-><code>GetSafeHwnd()</code>,m_nCmdShow);
::UpdateWindow(m_pMainWnd-><code>GetSafeHwnd()</code>);

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

shanzy22-Aug-05 21:49

22-Aug-05 21:49

wonderful && excellent! I catch it! Thank you very much!

And Thank you : Christian Graus,Jose Lamas Rios ,ThatsAlok

shanzy

WMI

YusufK22-Aug-05 10:52

YusufK

22-Aug-05 10:52

Hi,

Using Win32_classes I have wrote a code. I have some help from msdn. I am retrieving sound card's info, up to now everything is ok. But also I need to compare "vtProp.bstrVal" with a string like "char c[30]". I think , I should convert this "vtProp.bstrVal" to a string or convert string "vtProp.bstrVal" like variable. Do you have any suggestions?

Thanx...

while (pEnumerator)
{
HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1,
&pclsObj, &uReturn);

if(0 == uReturn)
{
break;
}

VARIANT vtProp;
VariantInit(&vtProp);
c=&(vtProp.bstrVal);
// Get the value of the Name property
hr = pclsObj->Get(L"ProductName", 0, &vtProp, 0, 0);
std::wcout <

Re: WMI

Christian Graus22-Aug-05 12:02

22-Aug-05 12:02

comutils.h contains a string class called _bstr_t. This class will take a bstr and return a char *. So

_bstr_t bt (myChar*);

Now you can cast bt to a char *.

Christian Graus - Microsoft MVP - C++

Re: WMI

YusufK23-Aug-05 7:59

YusufK

23-Aug-05 7:59

Thank you,

But my compiler have not found comutils.h . I am using Visual Studio 6.0, should I install any extension pack?

Re: WMI

Christian Graus23-Aug-05 13:27