C / C++ / MFC

17-Jun-10 16:34

well, i provided as many links to detailed explanations as i could stand to look up.

Re: inheriting std::vector

Emilio Garavaglia18-Jun-10 3:12

Emilio Garavaglia

18-Jun-10 3:12

Chris, those links are "things to be noted" not "the Bible".
The STL itself is designed by inheriting between classes that don't have virtual destructor. Think to iofstream versus istream and ostream

STL containers don't have virtual destructors because they are designed to be non-polymophic and to exist into a closed scope.

If you respect this, that means don't do things like (pseudocode)

vector* p = new myvector;
delete p; //worng: will destroy only "vector" not "myvector"

but just

{
   myvector v;
   //whatever you want with v, including vector functionality
}

you are in any case in a right position.

2 bugs found.
> recompile ...
65534 bugs found.
D'Oh! | :doh:

Re: inheriting std::vector

C^hris L^osinger18-Jun-10 11:17

18-Jun-10 11:17

i thought it would be better to tell the OP where to find relevant information, rather than to try explaining the entire topic and trying to find out which bits he needed to specifically worry about.

scan array of byte

rockago17-Jun-10 8:25

rockago

17-Jun-10 8:25

Heey guys,

Little question, long answer:P
How to find a array of byte in vc with readprocessmemory?
I need to find: 01 00 00 00 00 73 74 65 72 2F
How to do this:P

Niklas L17-Jun-10 8:34

17-Jun-10 8:34

I found someone who had the exact same question as yours over at Cheat Engine[^]. That guy got a reply he was satisfied with.

rockago17-Jun-10 8:48

rockago

17-Jun-10 8:48

I don't know how to express.So,I with his words.But he needs to Delphi and I need to the vc Poke tongue | ;-P

Niklas L17-Jun-10 9:11

17-Jun-10 9:11

So you are cheating even when asking questions? Big Grin | :-D

What is it you need help with? How to use ReadProcessMemory[^], or how to compare two memory blocks[^]?

What have you tried so far?

Enumwindows hangs (freezing) application any idea?

David Crow17-Jun-10 9:11

David Crow

17-Jun-10 9:11

What have you tried so far? Do you have a starting address from which to read?

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Man who follows car will be exhausted." - Confucius

ERLN17-Jun-10 8:07

ERLN

17-Jun-10 8:07

Hi I have using MFC dialog application. in that it is calling another dialog.
in 2nd dialog i am enumerating the windows using enumwindows api. after calling the enumwindows application is freezing or hanging. any idea about this.

Re: Enumwindows hangs (freezing) application any idea?

David Crow17-Jun-10 9:07

David Crow

17-Jun-10 9:07

Does your callback get called at all?

Re: Enumwindows hangs (freezing) application any idea?

rp_suman17-Jun-10 19:07

rp_suman

17-Jun-10 19:07

Please post the code snippet where the application hangs.
APIs never hang application, only the way of using it.
Something might went wrong in the callback.

--
"Programming is an art that fights back!"

Re: Enumwindows hangs (freezing) application any idea?

ERLN17-Jun-10 22:28

ERLN

17-Jun-10 22:28

Dialog1 ::Onok()
{

	HWND hShareWnd = NULL;
	UpdateData();
	bDesktopShareStarted = 	!bDesktopShareStarted ;
	if(bDesktopShareStarted)
	{
		int width = GetSystemMetrics(SM_CXSCREEN);
		int height = GetSystemMetrics(SM_CYSCREEN);
		int x = 0;
		int y =0;

		CVariableRegion VariableRgnDlg;   ////dialog 2 
		if(VariableRgnDlg.DoModal() ==IDOK)
		{
		
			hShareWnd = VariableRgnDlg.GetShareWindow();
			width = VariableRgnDlg.GetShareWidth();
			height = VariableRgnDlg.GetShareHeight();
			x = VariableRgnDlg.GetShareXPosition();
			y= VariableRgnDlg.GetShareYPosition();
			if(m_bEnableAVIRecording)
				EnableAVIRecording();
			else
				EnableAVIRecording(FALSE);
			//Session
			ZeroMemory(szBuffer,sizeof(szBuffer));
			GetDlgItemText(IDC_EDIT_CODE,szBuffer,sizeof(szBuffer));
			lLength = _tcslen(szBuffer) + 1 ; //reusing the same variable
			SetRegInfo(LASTUSED_SESSION,szBuffer,REG_SZ,&lLength);
			
			
			
			
			
			//Session pass
			ZeroMemory(szBuffer,sizeof(szBuffer));
			GetDlgItemText(IDC_EDIT_PASS,szBuffer,sizeof(szBuffer));
			lLength = _tcslen(szBuffer); //reusing the same variable
			SetRegInfo(LASTUSED_SESSION_PASS,szBuffer,REG_SZ,&lLength);
			
			
			
			
			//Client Name
			ZeroMemory(szBuffer,sizeof(szBuffer));
			GetDlgItemText(IDC_EDIT_CLIENT_NAME,szBuffer,sizeof(szBuffer));
			lLength = _tcslen(szBuffer); //reusing the same variable
			SetRegInfo(LASTUSED_USERNAME,szBuffer,REG_SZ,&lLength);
			
			
						
			
			//Record AVI 
			lLength = sizeof(m_bEnableAVIRecording); //reusing the same variable
			m_bEnableAVIRecording = IsDlgButtonChecked(IDC_CHECK_AVI_REC);
			SetRegInfo(LASTOPTION_AVI,(LPTSTR)&m_bEnableAVIRecording,REG_DWORD,&lLength);
			
			
			StartDesktopShare(hShareWnd,width,height,x,y,GetDlgItem(IDC_TARGETWND)->m_hWnd);
			GetDlgItem(IDC_BUTTON_DSK_SHARE)->SetWindowText(TEXT("Stop Share"));
		
		}
		else
		{
			StopDesktopShare();
			GetDlgItem(IDC_BUTTON_DSK_SHARE)->SetWindowText(TEXT("Start Share"));
			bDesktopShareStarted = 	!bDesktopShareStarted ;
		}

	
	}
	else
	{
		StopDesktopShare();
		GetDlgItem(IDC_BUTTON_DSK_SHARE)->SetWindowText(TEXT("Start Share"));
	}
}





dialog 2 code//
in dialog 2 on button click this function is called.
long CVariableRegion::GetWindowsList()
{
	HWND hListBox = NULL;
	TCHAR sWindowCount[100] = {0};
	int nWindowsCount = 0;
	CWnd *hDeskopWnd = NULL;
	TCHAR szWindowCountTitle[MAX_PATH]={0};

	hListBox = GetDlgItem(IDC_WIN_LIST)->m_hWnd;
	ListBox_ResetContent(hListBox);
	ZeroMemory(sWindowCount,sizeof(sWindowCount));
	ZeroMemory(szWindowCountTitle,sizeof(szWindowCountTitle));

	LoadString(GetModuleHandle(NULL),IDS_STRING_PLEASEWAIT,szWindowCountTitle,sizeof(szWindowCountTitle));
	SetDlgItemText(IDC_WIN_CNT,szWindowCountTitle);
	Sleep(100);

	hDeskopWnd = GetDesktopWindow() ;
	WindowsHandle ( hDeskopWnd -> m_hWnd, ( LPARAM ) hListBox ) ;
	EnumWindows ( WindowsHandle, ( LPARAM ) hListBox ) ; 
	nWindowsCount = ListBox_GetCount(hListBox);
	
	_stprintf(sWindowCount,TEXT("Windows : %d"),nWindowsCount);
	SetDlgItemText(IDC_WIN_CNT,sWindowCount);
	return 0;
}



BOOL CALLBACK WindowsHandle ( HWND hwnd, LPARAM lParam )
{

	DWORD       dwExtent;
	HDC         hDCListBox;
	HFONT       hFontOld;
	HFONT		hFontNew;
	TEXTMETRIC	tm;
	CWnd		*hWindow;
	CString		strTitle;
	SIZE		Size;
	TCHAR		szCurTitle[MAX_PATH]		={0};
	TCHAR		szCurParentTitle[MAX_PATH]	={0};
	HWND		hListBox;
	CWnd		*pComboBox;
	HWND		hWndListBox;
	long		lExtent;

	hWindow		= NULL;
	dwExtent	= 0;
	hDCListBox	= NULL;
	hFontNew	= NULL;
	hFontOld	= NULL;
	Size.cx		= 0;
	Size.cy		= 0;
	pComboBox	= NULL;
	hWndListBox = NULL;
	lExtent		= 0;
	hListBox	= ( HWND ) lParam ;


	//Get Current Window Handle
	hWindow = CWnd::FromHandle ( hwnd ) ;

	//GetCurrent Window Title
	hWindow -> GetWindowText ( strTitle ) ;
	
	//Check Window Visibility and Window Title Length
	if(hWindow->IsWindowVisible() && (strlen(strTitle) > 0 ) )
	{
		ZeroMemory(szCurTitle,sizeof(szCurTitle));
		ZeroMemory(szCurParentTitle,sizeof(szCurParentTitle));

		pComboBox = CWnd::FromHandle ( hListBox ) ;

		GetWindowText(GetParent(pComboBox->m_hWnd),szCurTitle,sizeof(szCurTitle));
		GetWindowText(GetParent(GetParent(pComboBox->m_hWnd)),szCurParentTitle,sizeof(szCurParentTitle));
		
	
		if( (_tcsicmp(szCurTitle,strTitle) != 0 ) && (_tcsicmp(szCurParentTitle,strTitle) != 0 ) )
			if(_tcsicmp(strTitle,TEXT("Program Manager")) !=0 )
			( ( CListBox * ) pComboBox )->AddString (strTitle ) ;


		//By default WS_HSCROLL of window sytle not supported for Listbox  for that following code are required.

		hWndListBox		= pComboBox->m_hWnd;


		hDCListBox = GetDC(hWndListBox);
			hFontNew = (HFONT)::SendMessage(hWndListBox, WM_GETFONT, NULL, NULL);
			hFontOld = (HFONT)SelectObject(hDCListBox, hFontNew);
			GetTextMetrics(hDCListBox,&tm);
			dwExtent = GetTextExtentPoint(hDCListBox, strTitle , (strlen(strTitle )+ tm.tmAveCharWidth),&Size);
			SelectObject(hDCListBox, hFontOld);
		ReleaseDC(hWndListBox, hDCListBox);

		lExtent = pComboBox->SendMessage(LB_GETHORIZONTALEXTENT);
		if(lExtent < Size.cx)
		{
			lExtent = Size.cx;
			pComboBox->SendMessage(LB_SETHORIZONTALEXTENT,lExtent);
		}
					
	}

	return TRUE ;
}

I pasted the code snippet for dialog 1 and dialog 2

A Doubt

Benjamin Bruno17-Jun-10 7:57

Benjamin Bruno

17-Jun-10 7:57

<br />
<br />
int i =2;<br />
int j = ++i + ++i;<br />
<br />
cout<<" value of j is : " << j;<br />
<br />

in the above code the output value of j is 8,I am confused about that.Please help?

Niklas L17-Jun-10 8:08

17-Jun-10 8:08

No need to be confused

++i => i = 3
++i => i = 4

+ => 4+4 = 8

C^hris L^osinger17-Jun-10 9:18

17-Jun-10 9:18

where does the 2nd '4' come from, in your bottom line ?

Niklas L17-Jun-10 9:20

17-Jun-10 9:20

There is only one instance of i, so i will be incremented twice before the addition occurs.

C^hris L^osinger17-Jun-10 9:23

17-Jun-10 9:23

Aescleal17-Jun-10 9:32

Aescleal

17-Jun-10 9:32

Just playing devil's advocate...

But you're not adding i twice, you're adding the results of the expression ++i which is either going to be 3 or 4 depending on how many times you've done the ++ operation.

Cheers,

Ash

Niklas L17-Jun-10 9:47

17-Jun-10 9:47

...but if you add 3 and 4 you will not get 8, and the OP would not have been confused in the first place. It would be a shame if once in a while you didn't get an unexpected result. (The testing department might disagree on that though)

Richard MacCutchan17-Jun-10 9:47

Richard MacCutchan

17-Jun-10 9:47

This is a common issue and the rules are: don't do this as the results are not guaranteed. Whatever answer you get you may get a different answer with another manufacturer's compiler. If you really need to evaluate such an expression you need to break it into steps like:

C++

int i = 2;
int j = ++i;
j += ++i;

It's time for a new signature.

Stephen Hewitt17-Jun-10 15:06

Stephen Hewitt

17-Jun-10 15:06

It's pretty subtle. Here's a breakdown of what's hapenning:

++i increments i (so i=3) and returns a reference to i.
The second ++i increments i (so i=4) and returns a reference to i.
The + is called with the two references. Both are dereferenced and added (4+4).

Steve

JobinG20-Jun-10 19:08

JobinG

20-Jun-10 19:08

 int i = 2;<br />
<br />
        int j = ++i + i++ + ++i + i++ + ++i;<br />
<br />
        cout<<"Value of j: "<<j;

The value getting for 'j' is 19. As you have said the three ++i statements will execute and the value of i become 5. How will execute the i++ statements? Could you please explain.

Stephen Hewitt21-Jun-10 15:00

Stephen Hewitt

21-Jun-10 15:00

Firstly there are two cases here, the pre-increment and (++i) the post-increment (i++). The pre-increment case increments the variable and returns a reference to it. The post-increment case copies the variable, increments the original and returns the copy.

Steve