C / C++ / MFC

Re: How do I use string as a param for CreateWindowEx function

6-Oct-06 19:00

Use

hwnd = CreateWindowEx( NULL,<br />
_T("AeroClass"),<br />
_T("Aerobatics by Scody"),...

WhiteSky

scody7-Oct-06 1:18

scody

7-Oct-06 1:18

I changed my project settings to use multi-byte character set and it worked!

Thanks very much!

Scody

Temporary pointer

Oliver1236-Oct-06 16:18

Oliver123

6-Oct-06 16:18

I cobbled this code together by trial and error. I put it in a global procedure and use it to change the value of an edit control in a dialog. This is kind of neat because it's the first way I have found to control a dialog item from outside the dialog. However, the MSFT MFC Reference says about CWnd::GetDlgItem(), "The returned pointer may be temporary and should not be used for later use."

What's up? What makes a pointer temporary? Would I have to get CWnd* pt everytime I want to use it?

CWnd* pt;
pt = (CWnd*)AfxGetApp()->m_pMainWnd->GetDlgItem(IDC_EDIT2);
pt->SetWindowText("JJJJJJJ");

I also note this works without using (CWnd*) cast. Use or not use (CWnd*)?

CWnd* pt;
pt = AfxGetApp()->m_pMainWnd->GetDlgItem(IDC_EDIT2); <-----no (CWnd*)
pt->SetWindowText("JJJJJJJ");

Re: Temporary pointer

Michael Dunn6-Oct-06 18:59

Michael Dunn

6-Oct-06 18:59

GetDlgItem() returns a CWnd* so the (CWnd*) cast does nothing.
MFC keeps per-thread maps of some objects, for example that's how it associates a CWnd and an HWND. If an MFC function creates a temp object - one that's not kept in a map - then the temp object may be deleted at any time after your function returns. That's why the docs say don't store the pointer. If you need a longer-lived object, use CWnd::FromHandle() or an equivalent.

--Mike--
Visual C++ MVP Cool | :cool:

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Can't get a file path from a windows dialog and pass it too a directX api call

BarryOg6-Oct-06 14:11

BarryOg

6-Oct-06 14:11

I'm trying to open a dialog box to the user and than take the filename they select and pass it too a DirectX api call which gets details about that file. I've been messing around with this for a few nights and I've got absolutely nowhere. I've read a lot about character encoding and although there are still a few blanks in my understanding I have a fairly good grasp of it. I'd imagine what I'm trying to do is simple enough and I'm running into pitfalls which are common place but no matter what I attempt to do I can't seem to get around these errors. Anyway here's my code, please take a look and if you could shed some light you'd really be doing me a huge favour.

I was given this in an earlier forum post, I really don't understand what it does, but it fixed an eariler problem I had so its in there for now.

#ifdef _UNICODE<br />
typedef wstring tstring;<br />
#else<br />
typedef string tstring;<br />
#endif

This is my function to display a file select dialog box and returns a tstring of the full path.

tstring openFile()<br />
{<br />
	OPENFILENAME ofn;       // common dialog box structure<br />
	TCHAR szFile[_MAX_PATH];       // buffer for file name<br />
	HANDLE test;<br />
<br />
	// Initialize OPENFILENAME<br />
	ZeroMemory(&ofn, sizeof(ofn));<br />
	ofn.lStructSize = sizeof(ofn);<br />
	ofn.hwndOwner = mainLoop.hWnd;<br />
	ofn.lpstrFile = szFile;<br />
	//<br />
	// Set lpstrFile[0] to '\0' so that GetOpenFileName does not <br />
	// use the contents of szFile to initialize itself.<br />
	//<br />
	ofn.lpstrFile[0] = '\0';<br />
	ofn.nMaxFile = sizeof(szFile);<br />
	ofn.lpstrFilter = _T("All\0*.*\0Text\0*.TXT\0");<br />
	ofn.nFilterIndex = 1;<br />
	ofn.lpstrFileTitle = NULL;<br />
	ofn.nMaxFileTitle = 0;<br />
	ofn.lpstrInitialDir = NULL;<br />
	ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;<br />
<br />
	// Display the Open dialog box. <br />
<br />
	if (GetOpenFileName(&ofn)==TRUE) <br />
		test = CreateFile(ofn.lpstrFile, GENERIC_READ,<br />
			0, (LPSECURITY_ATTRIBUTES) NULL,<br />
			OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,<br />
			(HANDLE) NULL);<br />
	<br />
<br />
<br />
	tstring temp (ofn.lpstrFile);<br />
<br />
	return temp;<br />
<br />
}

When I call this the contents of Info remain null, so I'm guessing what's happening here is the encoding of fileName is incorrect for this function.

fileName = openFile();<br />
	<br />
D3DXGetImageInfoFromFile(fileName.c_str(), &Info);

If I call it with the value hardcoded like so:

D3DXGetImageInfoFromFile(_T("F:\\Pictures\\ShannonTrip2006-PrintRun\\ShannonTrip2006 326.jpg"))

it works, it also works if I do the following:

fileName = _T("F:\\Pictures\\ShannonTrip2006-PrintRun\\ShannonTrip2006 326.jpg");<br />
	<br />
D3DXGetImageInfoFromFile(fileName.c_str(), &Info);

The memory of fileName in this call looks exactly the same as the memory used when I'm getting the value from openFile() yet one works and the other doesn't. Not sure where I can look after this, any help is greatly appreciated.

Re: Can't get a file path from a windows dialog and pass it too a directX api call

Hamid_RT6-Oct-06 19:20

Re: Can't get a file path from a windows dialog and pass it too a directX api call

6-Oct-06 19:20

You have problem with return value of fileName.c_str()?

WhiteSky

BarryOg7-Oct-06 1:38

BarryOg

7-Oct-06 1:38

Yes when I try to pass fileName.c_str() into the api call when I've gotten its value from the windows file dialog it returns an error, when I attempt it after setting its value with a literal wrapped in _T it works. The memory of the two looks the exact same so I can't tell why one is failing and the other isn't.

Re: Can't get a file path from a windows dialog and pass it too a directX api call

Hamid_RT7-Oct-06 2:48

Re: Can't get a file path from a windows dialog and pass it too a directX api call

7-Oct-06 2:48

I run your code and fileName.c_str() return file(full with path) but what error?

WhiteSky

BarryOg7-Oct-06 4:09

BarryOg

7-Oct-06 4:09

The api call returns 0x88760b59 which is D3DERR_INVALIDCALL, which means one of the parameters wasn't valid. The open file part isn't a problem that's getting the file and path out fine, its just when I pass what's being returned by that into a Unicode method I get a invalid call error.

waveOutGetID [modified]

kk30036-Oct-06 11:51

kk3003

6-Oct-06 11:51

Hi,

has anyone a idea how to find out the specific device_id for one of my installed soundcards?!
Playing via WAVE_MAPPER is no problem, but i need play on two different sound devices at the same time....

Please help me (maybe with a codesnippet).

Regards,
Alexander

P.S.: I am calling all available device via WaveOutDevsGetNum and its capabilities via WaveOutDevsCaps...

-- modified at 18:04 Friday 6th October, 2006

CreateProcess() anomaly

neilsolent6-Oct-06 9:21

neilsolent

6-Oct-06 9:21

Hi everyone

I am running the following piece of code on Windows 2000 and XP (except the code below has been simplified with error checking removed).
This code spawns a child process, which writes its output to a logfile called child.log.

The problem I am having is: if the child process is a command or batch file (example below), then child.log captures output of commands such as "dir",
however, for any processes that are launched from the batch script, such as perl.exe, all the output is lost. I don't know where the
output is going or why. I suspect I have done something wrong with handle inheritance somewhere.. any ideas??
I don't get the same problem if the child process is some other shell interpreter, such as bash.exe.

.........................

SECURITY_ATTRIBUTES secAttr;
secAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
secAttr.bInheritHandle = TRUE;
secAttr.lpSecurityDescriptor = NULL;

STARTUPINFO startupInfo;
::ZeroMemory((void*) &startupInfo, sizeof(STARTUPINFO));
startupInfo.cb = sizeof(STARTUPINFO);
startupInfo.dwFlags = STARTF_USESTDHANDLES;

PROCESS_INFORMATION processInfo;

startupInfo.hStdOutput = CreateFile(
"child.log",
GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ,
&secAttr,
CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_WRITE_THROUGH | FILE_FLAG_SEQUENTIAL_SCAN,
NULL);
startupInfo.hStdError = startupInfo.hStdOutput;

CreateProcess(
NULL,
"test.bat",
NULL,
NULL,
TRUE,
DETACHED_PROCESS,
NULL,
NULL,
&startupInfo,
&processInfo);

// Close handle because parent process has no further need for it:
CloseHandle(startupInfo.hStdOutput);

..................

Example of test.bat:
----------------------------

rem test.bat
rem dir command gives output in child.log, but "perl -v" does not !!

dir
perl -v
exit 0

cheers,
Neil

AuthFilt always display the logon page

Will88888886-Oct-06 8:49

Will8888888

6-Oct-06 8:49

Hello,

I downloaded the Microsoft ISAPI esample AuthFilt. I followed all the instructions built it and tried it. When I used the user name and password in the "C:\inetsrv\userdb.txt" to login, the login page always showed up.

Could somebody please help me and tell why that happened?

Thanks and best regards

William

Image sequence display in Dialog [modified]

Bighand20006-Oct-06 7:22

6-Oct-06 7:22

I have a number of images(100 or more) that need to be processed and displayed using MFC. The processing is very cpu intensive. I process the images in the main dialog, and display the result images in a child dialog, by calling the the Invalidate() and UpdateWindow() pair to redraw the child dialog after the processing of each image. And now the program is single threaded.

But the display freezes after some frames has been displayed correctly.

In the OnPaint() of the child dialog, I call this function:

void CDisplayDlg::ShowBitmap(CPaintDC *pdc, CBitmap* pBitmap)
{	
	
	BITMAP bm;
	
	pBitmap->GetBitmap(&bm);
	CDC dcMem;

	dcMem.CreateCompatibleDC(pdc);
	
	CBitmap* pOldBitmap=(CBitmap*) dcMem.SelectObject(pBitmap);
   	
	//Copy and resize the bitmap to the dialog window
	pdc->BitBlt(0,0,bm.bmWidth,bm.bmHeight,&dcMem,0,0,SRCCOPY);
	dcMem.SelectObject( pOldBitmap);
	DeleteDC(dcMem);
	
}

And this is the OnPaint():

void CDisplayDlg::OnPaint() 
{
	CPaintDC dc(this); // device context for painting
	
        // TODO: Add your message handler code here
	CFADlg *pWnd = (CFADlg *)GetParent();
	if(pWnd)
	{	
		//GDIPlusShowBitmap(&dc, &pWnd->m_bmpBitmap);
		ShowBitmap(&dc, &pWnd->m_bmpBitmap);
	}

	int m=ReleaseDC(&dc);
	TRACE("m: %d\n", m);
	// Do not call CDialog::OnPaint() for painting messages
}

After processing of all the images, the child dialog displays the last processed image. I have also tried using GDI+ to implement the showbitmap, but it has the same problem.

What should I do with this? At first I thought that was because I used up all the DC resources. Or maybe I need to use multithread it?

I will really appreciate any help from you. Thanks a lot!

-- modified at 14:21 Friday 6th October, 2006

led mike6-Oct-06 8:44

led mike

6-Oct-06 8:44

Bighand2000 wrote:
The processing is very cpu intensive.

Bighand2000 wrote:
the display freezes

Bighand2000 wrote:
maybe I need to use multithread it?

yes

led mike

Bighand20006-Oct-06 9:19

6-Oct-06 9:19

Thanks for your suggestion.

Hamid_RT6-Oct-06 8:48

Re: Image sequence display in Dialog [modified]

6-Oct-06 8:48

Did you use of thread or timer for read files because I think you read files and also you process files,right?
--------
And a question did you see PF usage on TaskManager when you run your program if you use of a wrong code then
PF usage will increase I had this problem for example It was 162MB but after run my program It was 300MB

WhiteSky

Bighand20006-Oct-06 9:22

6-Oct-06 9:22

WhiteSky wrote:
Did you use of thread or timer for read files because I think you read files and also you process files,right?
--------

I do not use any thread or timer for reading files. I just read in the image one by one, process it, display it, then write it out(this does not change anything with the display freeze problem). Generally, about 2 or 3 images can be processed each second.

-- modified at 15:29 Friday 6th October, 2006

Hamid_RT6-Oct-06 19:00

6-Oct-06 19:00

about 2 or 3 images can be processed each second if you have files with Dimensions 2331 x 3240 how long to read them?

WhiteSky

Bighand20007-Oct-06 4:29

7-Oct-06 4:29

My file is 720x480, grayscale uncompressed image( .pgm), size is about 330kB each. So it does not take much time to read.

I turned off the process step, just read in and display the images, but the display still freezes after about 100 frames(the freezing happens after about 20-50 fames when the process step is there).

Hamid_RT7-Oct-06 6:54

7-Oct-06 6:54

And after freeze what happen for your program it returns to normal state or no and one thing
did you trace your program line to line (I know Its hard) if yes what happen in this case its working or no

WhiteSky

Bighand20007-Oct-06 16:52

7-Oct-06 16:52

The calculation looks fine, since all the processed frames are written out as expected. After all the frames are done, the display is refreshed to show the last processed image.

So of all the steps for each frame: read in, process, display, write out, only display has problem: it freezes after some processed frames(maybe 20, maybe 50) are displayed.

Hamid_RT7-Oct-06 19:52

7-Oct-06 19:52

And what happen for PF usage on TaskManager? it increase or no

WhiteSky

Bighand200010-Oct-06 11:55

10-Oct-06 11:55

The PF usage is normal when the display freeze, no difference compared to when the display is ok.

I am thinking of DC resource leak. I wrote another simple program that just read in and display the images one by one, the display freeze after some images are read.

Hamid_RT10-Oct-06 18:43

Re: Image sequence display in Dialog [modified]

10-Oct-06 18:43

If you have this problem in new program how to read images?

WhiteSky

Bighand200021-Oct-06 15:37