Re: nsigned to char * - C / C++ / MFC Discussion Boards

Paul M Watt12-Oct-02 15:41

12-Oct-02 15:41

Not that I am aware of, you will need to implement your own version. As far as I can remember though, there is a sample implementation in MSDN that shows how you can implement this function for windows 95 and Windows NT 4.0.

Good Luck

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

Re: TransparentBlit and win 95

RobertC12-Oct-02 16:18

RobertC

12-Oct-02 16:18

Thanks, I will have a look.

CWinThread and m_bAutoDelete

Braulio Dez17-Oct-02 7:28

Braulio Dez

17-Oct-02 7:28

Hi,

I'm new using CWinThread, what I'm doing is to show a progress bar window, mean while the GUI of the main window is being updated.

All goes fine, but... when I have to finish the CWinThread I do it in this way:

pThread->m_pMainWnd->PostMessage(WM_CLOSE,0,0);
pThread->PostThreadMessage(WM_QUIT, 0, 0);
WaitForSingleObject(pThread->m_hThread, INFINITE);

To have this working, I have to set in the InitInstance of the CWinThread class, this flag to false:

m_bAutoDelete = FALSE;

Do you know why ?, Or what I'm doing wrong ?

Thanks in advance, Greetings
Braulio

Re: CWinThread and m_bAutoDelete

Joaquín M López Muñoz17-Oct-02 7:43

Joaquín M López Muñoz

17-Oct-02 7:43

Hola Braulio,

m_bAutoDelete=TRUE instructs the CWindThread object to delete itself upon exiting; that means that all member data of the thread (including m_hTread) gets deleted, so it would be wrong to refer to it in a call to WaitForSingleObject. Having m_bAutoDelete==FALSE, the object remains in memory after the thread exits for you to inspect its data as you please. Remember that in this case you have the responsibility of disposing of the thread when no longer needed with delete pThread.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: CWinThread and m_bAutoDelete

Braulio Dez17-Oct-02 7:55

Braulio Dez

17-Oct-02 7:55

Hola Joaquin !!, Qué tal ?

Yes, you are right, thanks for the info. Mmmm... I've seen there is not very clear info and samples about CWinThread in MSDN or here in Codeproject, I'm thinking about making a new article, with the Progress Bar Dialog stuff ( in a CWinThread), do you think it's a good idea ? Is there some article or thing about CWinthread that is interesting ?.

Gracias de nuevo Joaquin !, Un saludo
Braulio

Re: CWinThread and m_bAutoDelete

Joaquín M López Muñoz17-Oct-02 8:01

Joaquín M López Muñoz

17-Oct-02 8:01

There's a couple of articles in the threads section of CP dealing with worker and UI threads; I haven't looked at them in detail, so maybe you've got something new to add Smile | :)

Besides, the progress bar stuff can be useful, and publishing in CP is a lot of fun. Regards.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

nsigned to char *

Anonymous12-Oct-02 10:49

Anonymous

12-Oct-02 10:49

Hello,

I need convert an unsigned data type to a char *. How can I do this??

The problem is originated in ...

for(int counter=0; counter<house.length(); counter++)="" {

="" <i="">get_the_unsigned_from (house.room( counter );
convert_the_unsigned_to_char*;
append_(_char*_(_counter-1_)_,_char_*_(_counter_)

}

I'll appreciate your help!

Sp

Re: nsigned to char *

John Clayton12-Oct-02 10:53

John Clayton

12-Oct-02 10:53

well - you can simply go for a cast... or try stripping the sign bit.

--
John Clayton

Re: nsigned to char *

Michael Dunn12-Oct-02 12:07

Michael Dunn

12-Oct-02 12:07

See the VC forum FAQ (link at the top of this page)

--Mike--
Just released - 1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
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Hooking CWnd::OnIdle() without subclassing

John Clayton12-Oct-02 9:07

John Clayton

12-Oct-02 9:07

Hi Everyone

I am trying to find out how I can hook 'onidle' from within an AddIn module for VC6. I know (using AfxGetApp()) that I can get to the CWnd* instance for MSDEV, but how on earth do I tell this CWnd* guy that I'd like to be called back when OnIdle() is being called?

Ideally, I would like to do :
AfxGetApp()->TellMeAllAboutOnIdleEvents(my_callback_interface);

(of course, this method don't exist!)

This could all be explained by my MFC naievity as well. Is it something to do with CCommandTarget perhaps? Well, while I continue to flex my eyes at the included MFC docs I shall hope for a reply.

Any help is massively appreciated! Thank you.

--
John Clayton

Printing Debug Without Printer :: MFC

valikac12-Oct-02 6:08

valikac

12-Oct-02 6:08

Hi.

I want to debug code that manages printing. However, I do not own a printer or have access to one. Is it possible to get print preview to emulate a printer? I just need the program to show an sample of what the print would looks like.

Thanks,
Kuphryn

Re: Printing Debug Without Printer :: MFC

Joaquín M López Muñoz12-Oct-02 6:16

Joaquín M López Muñoz

12-Oct-02 6:16

Install a printer driver that manages PostScript (most, actually). Then, when printing, set the check box that reads "Print fo a file", rename the resulting output to .ps and use any utility (Ghostview, for instance) to see the results.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: Printing Debug Without Printer :: MFC

valikac12-Oct-02 6:31

valikac

12-Oct-02 6:31

Okay. Thanks.

Kuphryn

Nanosecond timer resolution for Windows OS

jrthatcher12-Oct-02 6:02

jrthatcher

12-Oct-02 6:02

I previously wrote a Visual C++ app to perform digital I/O functions on a Windows9x machine. I/O timing was controlled using delay loops and watching the I/O signals on a logic analyzer. I know this is a kluge way of doing I/O timing, but I haven't been able to find any information on a nanosecond resolution timer (besides FILETIME) for a Windows based system. I've tried QueryPerformanceFrequency/Counter, but alas, not enough resolution.

All was well until my in-house app started being installed on other PC's with Win2K and XP. So now I'm back to square one. Is it a hopeless cause trying to find a nanosecond resolution timer for Windows OS's? I've done GPS timing resolution before, but that requires a GPS receiver which is overkill for what we're trying to do.

Please help!

Nifer Dead | X|

Re: Nanosecond timer resolution for Windows OS

MaximE12-Oct-02 11:34

MaximE

12-Oct-02 11:34

The best you can get it a 100ns resolution. Search for the "multimedia timer" in MSDN.

CDC::DrawText

xeonboy12-Oct-02 5:36

xeonboy

12-Oct-02 5:36

Now, I wanna ask 2 questions about CDC::DrawText(...).

As you know, besides supplying the text to be drawn, you also gotta tell the function the bounding rectangle to draw the text in.

1) If we specify the bounding rectangle to be far much more larger than the text(for e.g : CRect(10,10,600,600) to hold just the word "Xeon", in small fonts), DrawText(...) will auto-shrink and auto-size the bounding rectangle to fit the size of the text, right?

2) Is this behaviour the same on all versions of Windows? MSDN doesn't say too much about this at all.

Please and thanks a lot! Smile | :)

......

Re: CDC::DrawText

Joaquín M López Muñoz12-Oct-02 6:13

Joaquín M López Muñoz

12-Oct-02 6:13

1. DT_CALCRECT will make the rect fit the size of the text drawn without any actual drawing. If you don't specify this switch, I think DrawText leaves the rect untouched.

2. Unless otherwise noted, functions tend to behave the same across OSs. I don't see any reason to think this is different for DrawText. Have you detected any anomaly?

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: CDC::DrawText

xeonboy12-Oct-02 16:25

xeonboy

12-Oct-02 16:25

Joaquín M López Muñoz wrote:
If you don't specify this switch, I think DrawText leaves the rect untouched.

Hi there and thanks a lot, Joaquin! But I do think that DrawText(...) do fit this rect to the overall size of the text.

I did an experiment on a dialog-based program with a grey background. I called CDC::DrawText(...) as in :

<br />
void CMyProgramDlg::OnPaint()<br />
{<br />
   //....irrelevant code....<br />
   else<br />
   {<br />
       CPaintDC dc(this);<br />
       dc.DrawText("I am Xeon.",CRect(10,10,1000,1000),NULL);<br />
       CDialog::OnPaint();<br />
   }<br />
}

And guess what? The text is drawn within a rectangle that fits the text exactly, cos' u see, the background color of the text is white, and the style is OPQAUE. And white against a grey background, we can easily see the size of the rect used to hold the text. Smile | :)

Joaquín M López Muñoz wrote:
. Unless otherwise noted, functions tend to behave the same across OSs. I don't see any reason to think this is different for DrawText. Have you detected any anomaly?

No.....I haven't a chance to detect any anomalies, cos' I don't have more than 1 OS to test out. But 'm always really suspicious of a same program running on different Windows OSes. I've heard that lotsof programs behave in different ways across different OSes, and that's a total headache.

Big Grin | :-D

......

Dev Studio AddIn - Getting OnIdle() to work.

John Clayton12-Oct-02 5:27

John Clayton

12-Oct-02 5:27

Hi All - I'd love to know how I can get DevStudio VC6 to fire calls at my Addin's OnIdle() method - or at least to tell me somehow it's not doing anything and that I could do something during idle time.

Since the addin's are not allowed to run their own message pump (aka DevStudio application model is not thread safe) I can't just go ahead and slap a message queue in there with a thread to manage it.

What I've got is a socket connection to another server WITHIN MY ADDIN, and I want to be able to check whether there's any input on the socket during idle time.

I was also wondering if I could create a another thread then kinda 'post' messages across this thread boundary - but it requires that I hook something into the DevStudio message loop - which I don't know how to get hold of.

Any help is massively appreciated! Thank you.

--
John Clayton

Locating *my* icon in the system tray

Taka Muraoka12-Oct-02 3:20

Taka Muraoka

12-Oct-02 3:20

Anyone know how to do this?

Spy shows the system tray as a single window (with no children) so getting the window rect for that is no problem but can I then locate where my icon is within the systray?

Is Winsock XP different??

zbyrat12-Oct-02 2:44

zbyrat

12-Oct-02 2:44

I have very strange behaviour of application. It´s transfer of data with TCP/IP. I´m using ovellaped WSARecv, WSASend. There was no problem on Windows 98, NT 4, 2000...but on XP it doesn´t work. For example, when transferring data block whom size exceed 3760 bytes, on W2000 is complete, but on XP is limited to 3760. I´m talking about tests on local machine, but on network was result similar(i´dont know exactly how many bytes was transferred).
Sorry, my English it´s not very good, but I believe you understand Smile | :)

Re: Is Winsock XP different??

Mike Nordell12-Oct-02 5:56

Mike Nordell

12-Oct-02 5:56

Maybe just the XP stack has a lower MTU? Start by checking that (getsockopt with SO_MAX_MSG_SIZE).

Re: Is Winsock XP different??

zbyrat12-Oct-02 6:22

zbyrat

12-Oct-02 6:22

Thanks but...maybe I said it wrong, I talked about connection oriented socket, not UDP.

Memory leak

suresh_sathya12-Oct-02 2:23

suresh_sathya

12-Oct-02 2:23

Hi i tried to reduce my memory leak.I reduced that,but still only few bytes of memory leak.I checked everything,but still i cant find.Pl anybody can help.Thanks in advance.

HRESULT hr;
IXMLDOMDocument2 *pIXMLDOMDocument2=NULL;
IXMLDOMNodeList *pIXMLDOMNodeList=NULL;
IXMLDOMNode *pIXMLDOMNode=NULL,*pIXMLDOMNode1=NULL;
IXMLDOMNamedNodeMap *pIXMLDOMNamedNodeMap1 = NULL;
VARIANT_BOOL boolvalue;
long Tablelen;
CComVariant Tablename;

hr = CoInitialize(NULL);
hr = CoCreateInstance(CLSID_DOMDocument, NULL, CLSCTX_INPROC_SERVER,
IID_IXMLDOMDocument2, (void**)&pIXMLDOMDocument2);
CComVariant varValue="testing.xml";
if (FAILED(hr))
return(hr);
if(SUCCEEDED(hr))
{

hr=pIXMLDOMDocument2->load(varValue,&boolvalue);
pIXMLDOMDocument2->selectNodes((_bstr_t)"DATABASE/TABLE[@Left]",&pIXMLDOMNodeList);
pIXMLDOMNodeList->get_length(&Tablelen);
HWND hListBox=GetDlgItem(hDlg,IDC_LIST);
pIXMLDOMNodeList->reset();

for(int i=0;i< Tablelen;i++)
{

pIXMLDOMNodeList->get_item(i,&pIXMLDOMNode);
pIXMLDOMNode->get_attributes(&pIXMLDOMNamedNodeMap1);
pIXMLDOMNode->Release();
pIXMLDOMNode=NULL;
pIXMLDOMNamedNodeMap1->getNamedItem((_bstr_t)"Name",&pIXMLDOMNode1);
pIXMLDOMNode1->get_nodeValue(&Tablename);
SendMessage(hListBox,LB_ADDSTRING,0,(LPARAM)(char *)(_bstr_t)Tablename);
pIXMLDOMNode1->Release();
pIXMLDOMNode1=NULL;
pIXMLDOMNamedNodeMap1->Release();
pIXMLDOMNamedNodeMap1=NULL;

}

CHECK_AND_RELEASE(pIXMLDOMDocument2);
CHECK_AND_RELEASE(pIXMLDOMNode1);
CHECK_AND_RELEASE(pIXMLDOMNodeList);
CHECK_AND_RELEASE(pIXMLDOMNode);
CHECK_AND_RELEASE(pIXMLDOMNamedNodeMap1);

}

CoUninitialize();

Re: Memory leak

MaximE12-Oct-02 11:29

MaximE

12-Oct-02 11:29

Jesus!!! Does this code work???

<br />
(_bstr_t)"DATABASE/TABLE[@Left]"<br />

What is this? Never, never do like this. Do:

<br />
_bstr_t(OLESTR("DATABASE/TABLE[@Left]"))<br />

<br />
pIXMLDOMNode->Release();<br />
pIXMLDOMNode=NULL;<br />

It's not bad, but pIXMLDOMNode = 0 is enough.

<br />
(LPARAM)(char *)(_bstr_t)Tablename<br />

Should be:

<br />
reinterpret_cast<LPARAM>(static_cast<TCHAR*>(_bstr_t(Tablename)))<br />

Such a bad cast should be explicit.

<br />
pIXMLDOMNode->get_attributes(&pIXMLDOMNamedNodeMap1);<br />

You are working with very smart pointer. Instead, do like this:

<br />
pIXMLDOMNamedNodeMap1 = pIXMLDOMNode->attributes;<br />

What is:

<br />
CHECK_AND_RELEASE(pIXMLDOMDocument2);<br />

May be it a:

<br />
#define CHECK_AND_RELEASE(x) x->AddRef()<br />

I don't know.

Summary.
1. Never, never use c-casts (like (_bstr_t)x, (LPARAM)y, etc). They are the worst evil, unless you damn sure that you do. It's very hard to find a bug in a such code.
2. Read about _com_ptr_t. Learn how it's intended to use.
3. Avoid macros.
4. Optional, but strongly recommended. Get a Stroustrup.

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