Using Property Pages to Display ODBC Database - C / C++ / MFC Discussion Boards

11-Mar-02 13:18

Can sombody tell me why this won't Beep? Cw is derived from CWinThread and Run() is supposed to be executed so what gives?

//////////////////////////////////
class Cw : public CWinThread
{
public:
int Run();
Cw();
virtual ~Cw();
};

Cw::Cw(){}

Cw::~Cw(){}

int Cw::Run()
{
Beep(1000,500);
return 0;
}
///////////////////////

elsewhere in the program:

Cw* w = new Cw();
w->CreateThread();

Re: too simple to work?

Joaquín M López Muñoz11-Mar-02 20:14

Joaquín M López Muñoz

11-Mar-02 20:14

You must override CWinThread::InitInstance. This method by default returns FALSE thus preventing the call to CWinThread::Run.
As a sidenote, I assume you're doing this as a simple test and do not plan to base any actual code on this way of overriding CWinThread::Run: this method has to provide some sort of message pump (which is what does by default). To run separate tasks, it is better to use worker threads.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: too simple to work?

12-Mar-02 4:47

Thank Joaquin, I'll give it a try. Actually, I need a thread with a message pump because i need to send it commands to do things. I can't figure out how to get message queue on a workerthread so I'm using a UI thread. I plan to put my own GetMessage() call into Run(). I will not be using this thread to service an UI elemets though. The only other thing that I know Run() does is call OnIdle(). Can I safly not call OnIdle() - I don't plan to overide it?

Re: too simple to work?

Atila12-Mar-02 5:25

Atila

12-Mar-02 5:25

what?
I think you answered the wrong guy.
Bye

Re: too simple to work?

12-Mar-02 5:27

Joaquín,

I tried what you said and overriding CWinThread::InitInstance works. Thanks! Now I have another question. If I declare several instances of this class they all seem to share the same variables. Maybe I am not saying that right so I will show you the code:

class Cw : public CWinThread
{
public:
DWORD delay;
DWORD freq;

BOOL InitInstance();
int Run();
Cw();
virtual ~Cw();
};

Cw::Cw()
{ delay = 0;
freq=1000;
}

Cw::~Cw(){}

int Cw::Run()
{ Sleep(delay);
Beep(freq,500);
return 0;
}

BOOL Cw::InitInstance(){Return TRUE;}

////////////////////////
Then i have four of the instances and i think i should hear 4 tones one after the other but i don't. Are they all sharing the same delay and freq?

w = new Cw();
w->freq=5000;
w->CreateThread();

x = new Cw();
x->delay=500;
x->freq=2000;
x->CreateThread();

y = new Cw();
y->delay=1000;
y->freq=1000;
y->CreateThread();

z = new Cw();
z->delay=1500;
z->freq=500;
z->CreateThread();

///////////////////////////////////////////////
The above code should sound like this:

w = new Cw();
w->freq=5000;
w->CreateThread();

Sleep(500);
x = new Cw();
x->freq=2000;
x->CreateThread();

Sleep(500);
y = new Cw();
y->freq=1000;
y->CreateThread();

Sleep(500);
z = new Cw();
z->freq=500;
z->CreateThread();

Re: too simple to work?

12-Mar-02 5:41

Joaquín,
Please ignore my message above. It was a bad test. If I change the values it will work better. Thanks again for your help.

(But I still wonder about my OnIdle question: The only other thing that I know Run() does is call OnIdle(). Can I safly not call OnIdle() - I don't plan to overide it? )

Here is how I getting my test to work (I increased the delay):
//Sleep(500);
x = new Cw();
x->delay=3000;
x->freq=2000;
x->CreateThread();
//Sleep(500);
y = new Cw();
y->delay=6000;
y->freq=1000;
y->CreateThread();
//Sleep(500);
z = new Cw();
z->delay=9000;
z->freq=500;
z->CreateThread();

Re: Hello again !

Atila12-Mar-02 5:57

Atila

12-Mar-02 5:57

I'm not the guy you want to chat with.
please pay attention to my question ...about ocx, I had nothing to do with your subject.
Bye.

Using Property Pages to Display ODBC Database

dsouthard11-Mar-02 12:39

dsouthard

11-Mar-02 12:39

I've been trying to return data from an ODBC database and display it in a tabbed dialog (property page). The code compiles just fine, but I get a runtime error during execution. Specifically,

ERROR MESSAGE:

<br />
TRACE0("ASSERT_VALID fails with NULL pointer.\n");<br />
        if (AfxAssertFailedLine(lpszFileName, nLine))<br />
            AfxDebugBreak();<br />
        return;     // quick escape<br />

I know the CRecordset class I created works fine (I've used it before in a single dialog page). The problem seems to occur during data exchange in the CPropertypage class. Here's the code that is suspect:

CPROPERTYPAGE SOURCE:

<br />
CPersonalData::CPersonalData() : CPropertyPage(CPersonalData::IDD)<br />
{<br />
    //{{AFX_DATA_INIT(CPersonalData)<br />
    m_pSet = NULL;<br />
    //}}AFX_DATA_INIT<br />
}<br />
<br />
void CPersonalData::DoDataExchange(CDataExchange* pDX)<br />
{<br />
    CPropertyPage::DoDataExchange(pDX);<br />
    //{{AFX_DATA_MAP(CPersonalData)<br />
    DDX_FieldText(pDX, IDC_TITLE, m_pSet->m_TITLE, m_pSet);<br />
    //}}AFX_DATA_MAP<br />
}<br />
<br />
CRecordset* CPersonalData::OnGetRecordset()<br />
{<br />
    return m_pSet;<br />
}<br />

In addition, m_pSet is defined in the header file for the CPropertypage as follows:

CPROPERTYPAGE HEADER:

<br />
class CPhysiciansListSet;<br />
<br />
class CPersonalData : public CPropertyPage<br />
{<br />
    DECLARE_DYNCREATE(CPersonalData)<br />
<br />
// Construction<br />
public:<br />
    CPersonalData();<br />
    ~CPersonalData();<br />
<br />
    virtual BOOL PreTranslateMessage (MSG* pMsg);<br />
<br />
// Dialog Data<br />
    //{{AFX_DATA(CPersonalData)<br />
    enum { IDD = IDD_PERSONALDATA };<br />
    CPhysiciansListSet* m_pSet;<br />
    //}}AFX_DATA<br />
};<br />

Any suggestions would be GREATLY appreciated. I've been screwing around with this app for a week now on this one problem and I'm about to go crazy.

Thanks in advance.

CHtmlView question

C^hris L^osinger11-Mar-02 12:22

C^hris L^osinger

11-Mar-02 12:22

I have a CHtmlView loaded with some HTML that i generate on the fly (loaded with IPersistStreamInit). it works fine - everything displays properly - yay.

the problem is when i try to do links within the document: links like <a href="#somelink">..</a> to <a name="somelink">.

if i hit one of these, the browser takes me to a page that says "blank#somelink", not to the "somelink" on the original page.

since i'm loading this HTML stream dynamically, i can't use the res:// "protocol" and, "file://" doesn't work...

any ideas?

-c

Smaller Animals Software, Inc.
You're the icing - on the cake - on the table - at my wake. _{Modest Mouse}

AfxGetMainWnd() from a Worker Thread

Giles11-Mar-02 11:03

Giles

11-Mar-02 11:03

I nned to be able to get the main frame window from a worker thread with no GUI component. AfxGetMainWnd() get the main window for the current thread - the worker thread and so returns null.

Any ideas on how to get the MainFrame from the primary thread?

Thanks,

Giles

Re: AfxGetMainWnd() from a Worker Thread

Morozov Alexey11-Mar-02 12:20

Morozov Alexey

11-Mar-02 12:20

Pass HWND of MainFrame through thread parameters and then create CWnd object by CWnd::FromHandle(HWND) function in workeer thread

Re: AfxGetMainWnd() from a Worker Thread

Giles12-Mar-02 12:29

Giles

12-Mar-02 12:29

I thought of passing the handle, but was not sure if it would be okay from another thread. Despite that, I am updainting another window, but need to be able to get at the promary thread so I can attach to the Frane Window, and them the Status Bar.

Thanks,

Giles

Re: AfxGetMainWnd() from a Worker Thread

Nish Nishant11-Mar-02 14:04

Nish Nishant

11-Mar-02 14:04

Try AfxGetApp( )->m_pMainWnd

Nish

Bow wow wow,
Yippee yo yippee yay,
My miniputt high,
Is now 30 yay.

Re: AfxGetMainWnd() from a Worker Thread

Giles12-Mar-02 12:26

Giles

12-Mar-02 12:26

Thanks Nish, will check it out.

Giles

CObArray - Destructors for CObject

dazinith11-Mar-02 10:36

dazinith

11-Mar-02 10:36

Hio again.. I have a class (CCompanyHandler) which loads and saves a CObArray which is full of CObjects. The load file function calls the CObject constructors, and I'm trying to figure out how to destruct all of these objects created when loaded. I figure if I can overload the CCompanyHandler destructor then I should be able to have it destruct all of the CObjects, but I still have some sort of memory leak. Here is a trace:

CCompanyHandler:Constructor
CCompanyHandler:LoadFile
CCompany:Contructor <+ 1

CCompanyHandler:Constructor
CCompanyHandler:LoadFile
CCompany:Contructor <+ 2

CCompanyHandler:Constructor
CCompanyHandler:LoadFile
CCompany:Contructor <+ 3
CCompanyHandler:LoadFile
CCompany:Contructor <+ 4

CCompanyHandler:Destructor
CCompany:Destructor <- 3
CCompanyHandler:Destructor
CCompany:Destructor <- 2
CCompanyHandler:Destructor
CCompany:Destructor <- 1

As you can see the LoadFile() function of CCompanyHandler is what calls the constructors for the objects as it reads them.

TRACE("CCompanyHandler:LoadFile\n");
try
{
CFile fileMyFile(m_strFileName,CFile::modeRead + CFile::modeNoTruncate); //open file for reading
CArchive arRead(&fileMyFile, CArchive::load); //open archive for loading
m_oaCompanies.Serialize(arRead); //call serialize function to populate m_oaCompanies
arRead.Close(); // close archive
fileMyFile.Close(); // close file
return 1;
}

My problem is that if I call the loadfile() function multiple times it will keep creating instances of CCompany, and then my destructor doesn't get rid of it.. here is what my destructor does:

TRACE("CCompanyHandler:Destructor\n");
if (GetSize() > 0)
for (int i = 0; i < GetSize(); i++)
((CCompany*)m_oaCompanies[i])->~CCompany();

As you can see this only calls the destructor for each of the objects in the CObArray, not all of the objects which were actually made by the loadfile() function..

basicly i am clueless on proper destruction right now, and I'm getting tons of memory leaks when I debug, any suggestions on proper destruction of pointers and such will be MOST appreciated.

-dz

ODBC and ExecuteSQL

Yousuf11-Mar-02 10:04

Yousuf

11-Mar-02 10:04

hi i connected an access database thru classwizard by creating a recordset class and connecting the database thru the following dialog. how do i run executesql command to acess related tables since i cannot find an automatically generated CDatabase class

Re: ODBC and ExecuteSQL

Carlos Antollini11-Mar-02 10:46

Carlos Antollini

11-Mar-02 10:46

Do you want to run a Query or execute a SQL Statement?;)

Regards

Carlos Antollini.
Sonork ID 100.10529 cantollini

Re: ODBC and ExecuteSQL

Yousuf12-Mar-02 9:21

Yousuf

12-Mar-02 9:21

how do i do both...

Which software updates NT to MSVCRT.DLL (6.00.8797)

Hoang Le11-Mar-02 9:05

Hoang Le

11-Mar-02 9:05

Hi all:

Do you know which software, service pack updates WinNT from older version of MSVCRT.DLL to newer ? (e.g MSVCRT.DLL 5.00.70220 -> 6.00.8797)

Thanks.

Hoang Le

Re: Which software updates NT to MSVCRT.DLL (6.00.8797)

Derek Waters11-Mar-02 11:28

Derek Waters

11-Mar-02 11:28

I don't, but you should check:

http://support.microsoft.com/servicedesks/fileversion/dllinfo.asp?fr=0&sd=msdn

which is MSDN's DLL database. Enter the dll name and it tells you all the versions and what they are installed by.

Hope this helps.

------------------------
Derek Waters
derek@lj-oz.com

Transparency and IPicture

Derek Lakin11-Mar-02 8:46

Derek Lakin

11-Mar-02 8:46

I have a wrapper around the IPicture interface for drawing Gifs and jpegs that it is then used in an extended CStatic class. The code below shows the wrapper Render function which is called from the CStatic-derived OnPaint handler (also shown):

// m_pict is a CPictureSSL
void CPictureCtrlSSL::OnPaint()
{
	CPaintDC dc(this);
	if (m_pict) {
		CRect rcClient;
		GetClientRect(&rcClient);
		CRect rcImage(CPoint(0,0),m_pict.GetImageSize());
		CRect rc;
		rc.IntersectRect(&rcImage, &rcClient);
		m_pict.Render(&dc, rc);
	}
}

// m_spIPicture is an ATL smart pointer to IPicture
BOOL CPictureSSL::Render(CDC* pDC, CRect rc, LPCRECT prcMFBounds) const
{
   ASSERT(pDC);

   if (rc.IsRectNull()) {
      CSize sz = GetImageSize(pDC);
      rc.right = sz.cx;
      rc.bottom = sz.cy;
   }
   long hmWidth,hmHeight; // HIMETRIC units
   GetHIMETRICSize(hmWidth, hmHeight);
   m_spIPicture->Render(*pDC, rc.left, rc.top, rc.Width(), rc.Height(),
      0, hmHeight, hmWidth, -hmHeight, prcMFBounds);

   return TRUE;
}

This all works fine, my question is: How can I get the CPictureSSL::Render function to paint a specified colour as transparent? I though if I did m_spIPicture->Render() to a different DC I could then do the necessary bit blits to get the right effect, but I don't know enough to make it work. Any ideas?

Derek Lakin.

I wish I was what I thought I was when I wished I was what I am.

Salamander Software Ltd.

SIMPLE QUESTION

11-Mar-02 8:20

can i write a games like tetris or pacman using MFC or do i have to write it in windows API using C????

Re: SIMPLE QUESTION

Christian Graus11-Mar-02 8:23

Christian Graus

11-Mar-02 8:23

You can use MFC. You'd be better to use DirectDraw than GDI, and there's not much POINT in using MFC if your program is going to mainly be worried about drawing your game, but there is no reason you can't do so if you desire.

Christian

The tragedy of cyberspace - that so much can travel so far, and yet mean so little.

"I'm thinking of getting married for companionship and so I have someone to cook and clean." - Martin Marvinski, 6/3/2002

Re: SIMPLE QUESTION

Mazdak11-Mar-02 9:14

Mazdak

11-Mar-02 9:14

There is an sample code in CP,I thing it was in DirectX or OpenGL part,its tetris game.

Mazy

"So,so you think you can tell,
Heaven from Hell,
Blue skies from pain,...
How I wish,how I wish you were here."
Wish You Were Here-Pink Floyd-1975

Edit Boxes\ Rich Edit

11-Mar-02 8:18

How do i set it so that i enter a number in one edit box and then have it add to or subtract from a read-only. I am trying to write a program for a class that is sort of like a jeopardy game with questions and answers and i cant get the score keeper to work.

Please E-mail me Cool | :cool:

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