Re: how do u get the arrow key events in a window?? - C / C++ / MFC Discussion Boards

toxcct9-Dec-04 23:55

9-Dec-04 23:55

hi everybody,

i have a little problem (maybe very easy to solve for some), but i can't find out how to solve it.

it is about tab controls (CTabCtrl) and the way to set controls in it.
actually, i have many texts (CStatic) which i would like to appear only depending on the selected tab. I cannot "attach" my static texts with the Tab control directly in the dialog editor, so how could i do ?
I only found that i initialize the tab control in OnInitDialog() (dialog-based application) ; and TCN_SELCHANGE overload allow me to catch a tab selection change.

thanks in advance for your answers.

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: How to use CTabCtrl

Mircea Puiu10-Dec-04 0:41

Mircea Puiu

10-Dec-04 0:41

See the following on http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/HTML/_core_using_ctabctrl.asp[^]

Using CTabCtrl

A "tab control" is analogous to the dividers in a notebook or the labeled folders in a file cabinet. Use the tab control, represented by class CTabCtrl, to show multiple pages of information or controls to a user, one at a time, in a format that suggests a peer or logical relationship between each page.

What do you want to know more about?
Tab Controls and Property Sheets
Tab Control Examples
Tabs and Tab Control Attributes
Making Owner-Drawn Tabs
Working with a Tab Control
Creating the Tab Control
Adding Tabs to a Tab Control
Processing Tab Control Notification Messages

SkyWalker

Re: How to use CTabCtrl

Maximilien10-Dec-04 0:41

Maximilien

10-Dec-04 0:41

you need to create pages for each tab.

Those pages are CPropertySheet. You can create dialogs, one for each tab, in the resource editor, and create the pages when you create the CTabCtrl.

when the dialog receives a TCN_SELCHANGE, you simply have to show/hide the appropriate propertysheet.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: How to use CTabCtrl

Cedric Moonen10-Dec-04 0:55

Cedric Moonen

10-Dec-04 0:55

If you just need a Tab control on your dialog, then you can use a CPropertySheet instead (just look at the MSDN to see how to use it): you will suply a dialog resource for each PropertyPage inside of it.
Otherwise, if your Tab control is included in an existing dialog (with other controls,...), take a look at this article: http://www.codeproject.com/tabctrl/ctabctrlssl.asp[^]

Hope this helps

:(( Help in CTypedPtrList / Clist

M AZZAAAM9-Dec-04 23:16

M AZZAAAM

9-Dec-04 23:16

Hi!
I m a beginner in VC++. I just started working on a project in VC++ 6.0. I am developing an SDI application. I am using template class :

CTypedPtrList <coblist, cmytype*=""> m_MyList;

in the document to get all values from database.
I populate the list in the initial update function of VIEW.
class CMyType : public CObject
{
HTREEITEM hti;
CString sName;
CString sID;
int nCount;
};
CMyType *pNT = new CMyType();
GetDocument()->m_myListofNodes.AddTail(pNT);

On closing the application, I get following error:

ERROR # 1
/////////////////////////////////////////////////////////////
MySystem - Untitled: MySystem.exe - Application Error
//////////////////////////////////////////////////////////////

The instruction at "0x10213035" refrenced memory at "0x00000015".
The memory could not be "read".
Click on OK to terminate the program.

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

If i try to delete the item from list, then window pops up saying that tell this problem to Microsoft.

ERROR#2
////////////////////////////////////////////////////////////
"MySystem MFC Application has encountered a problem and needs to close. We are sorry for the inconvenience."
On pressing DONT SEND, it gives the ERROR # 1.

If application is run in Debug mode, then it gives

ERROR # 3
///////////////////////////////////////////////////////////////
Unhandled exception in MySystem.exe (MSVCRTD.DLL):0xC0000005 Access violation

By pressing OK, it takes me to CBHEAP.C file at:

// unlink entry from list
pPrev->pEntryPrev->pEntryNext = pPrev->pEntryNext;
pPrev->pEntryNext->pEntryPrev = pPrev->pEntryPrev;
...
I really dont know whats going on ...
It will be really pleasant if any one can help me out.
Thnx

Pb using the OFN_NOCHANGEDIR flag

Forest20049-Dec-04 22:32

Forest2004

9-Dec-04 22:32

I want to not save the directory browse in a cfiledialog.
To do this I use the OFN_NOCHANGEDIR flag as it is said everywhere.
That doesn't work Frown | :-(

(
The directory is saved in spite of the OFN_NOCHANGEDIR flag.

Does anyone know this problem? How can I solve it?

Thanks for your help

Forest

how do u get the arrow key events in a window??

namaskaaram9-Dec-04 22:32

namaskaaram

9-Dec-04 22:32

how do u get the arrow key events in a window??what is the handler uses this??

Re: how do u get the arrow key events in a window??

ThatsAlok10-Dec-04 0:00

ThatsAlok

10-Dec-04 0:00

Trap Window WM_KEYDOWN Message and check nChar (in mfc) and wParam( in Win32api) for these code

VK_LEFT or 25 --> LEFT ARROW key  
VK_UP or 26  -->UP ARROW key  
VK_RIGHT or 27  -->RIGHT ARROW key  
VK_DOWN or 28  --> DOWN ARROW key

-----------------------------
"I Think this Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk

Creation of DLL from ActiveX control

tspramod9-Dec-04 22:25

tspramod

9-Dec-04 22:25

Hi,

we have an active x controls for webcam interface and i need to create a DLL with VC and use the same in a 3rd party application.
i.e i need to control the webcam through DLL

During creation of the DLL i dont have any issues, while calling the function from a console application - am getting windows assertion failed error..?

Can anyone guide me the settings if i need to make any inorder to control the dll which has activex in it..

Thanks in advance,
Pramod.

Converting Hex number to Dec number

Mythri.B.L9-Dec-04 21:38

Mythri.B.L

9-Dec-04 21:38

Hello,

Can anyone help me out with a function for converting hex numbers to dec numbers?

Thanks
Mythri

Re: Converting Hex number to Dec number

ThatsAlok9-Dec-04 21:50

ThatsAlok

9-Dec-04 21:50

Little Hack

char strDex[10];
int hex=0x10,iDec;
 sprintf(strDec,"%d",hex);

iDec=atoi(strDec);

-----------------------------
"I Think this Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk

Re: Converting Hex number to Dec number

ThatsAlok9-Dec-04 21:50

ThatsAlok

9-Dec-04 21:50

Little Hack

char strDex[10];
int hex=0x10,iDec;
 sprintf(strDec,"%d",hex);

iDec=atoi(strDec);

and iDec contain required Decimal Number

-----------------------------
"I Think this Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk

Re: Converting Hex number to Dec number

Cedric Moonen9-Dec-04 21:56

Cedric Moonen

9-Dec-04 21:56

Numbers are just numbers ! It's just their representation that changes !
For example if you have an integer that is equal to 5, it's binary representation will be 0101, it's hexadecimal representation will be 0x5 and it's decimal representation will be 5. But it is still the same number !!

So your question makes non-sense. Or maybe you want to ask how to print it in hex representation or decimal representation ?? Or maybe you want to convert a string that holds an hex number into a dec number ?? Or what else ... ?

So be more precise in your question.

Re: Converting Hex number to Dec number

Mircea Puiu10-Dec-04 0:24

Mircea Puiu

10-Dec-04 0:24

You get exactly the same, as hex and dec (and other more) are different representations of the same number!

SkyWalker

Could anyone help me to comment these code in detail?

LiYS9-Dec-04 21:32

LiYS

9-Dec-04 21:32

/*I copy these code from Charles Petzold's Programming Windows. The functions in the WM_PAINT Message confused me a lot. Is there anyboday kindly enough to add comments to these function in details, thank you!
*/
#include <windows.h>

#define ID_TIMER 1

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("DigClock") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;

wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc = WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;

if (!RegisterClass (&wndclass))
{

MessageBox (NULL, TEXT ("Program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}

hwnd = CreateWindow (szAppName, TEXT ("Digital Clock"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;

ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;

while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
return msg.wParam ;
}

void DisplayDigit (HDC hdc, int iNumber)
{
static BOOL fSevenSegment [10][7] = {
1, 1, 1, 0, 1, 1, 1, // 0
0, 0, 1, 0, 0, 1, 0, // 1
1, 0, 1, 1, 1, 0, 1, // 2
1, 0, 1, 1, 0, 1, 1, // 3
0, 1, 1, 1, 0, 1, 0, // 4
1, 1, 0, 1, 0, 1, 1, // 5
1, 1, 0, 1, 1, 1, 1, // 6
1, 0, 1, 0, 0, 1, 0, // 7
1, 1, 1, 1, 1, 1, 1, // 8
1, 1, 1, 1, 0, 1, 1 } ; // 9

static POINT ptSegment [7][6] = {
7, 6, 11, 2, 31, 2, 35, 6, 31, 10, 11, 10,
6, 7, 10, 11, 10, 31, 6, 35, 2, 31, 2, 11,
36, 7, 40, 11, 40, 31, 36, 35, 32, 31, 32, 11,
7, 36, 11, 32, 31, 32, 35, 36, 31, 40, 11, 40,
6, 37, 10, 41, 10, 61, 6, 65, 2, 61, 2, 41,
36, 37, 40, 41, 40, 61, 36, 65, 32, 61, 32, 41,
7, 66, 11, 62, 31, 62, 35, 66, 31, 70, 11, 70 } ;

int iSeg ;

for (iSeg = 0 ; iSeg < 7 ; iSeg++)
if (fSevenSegment [iNumber][iSeg])
Polygon (hdc, ptSegment [iSeg], 6) ;
}

void DisplayTwoDigits (HDC hdc, int iNumber, BOOL fSuppress)
{
if (!fSuppress || (iNumber / 10 != 0))
DisplayDigit (hdc, iNumber / 10) ;
OffsetWindowOrgEx (hdc, -42, 0, NULL) ;
DisplayDigit (hdc, iNumber % 10) ;
OffsetWindowOrgEx (hdc, -42, 0, NULL) ;
}

void DisplayColon (HDC hdc)
{
POINT ptColon [2][4] = { 2, 21, 6, 17, 10, 21, 6, 25,
2, 51, 6, 47, 10, 51, 6, 55 } ;

Polygon (hdc, ptColon [0], 4) ;
Polygon (hdc, ptColon [1], 4) ;

OffsetWindowOrgEx (hdc, -12, 0, NULL) ;
}

void DisplayTime (HDC hdc, BOOL f24Hour, BOOL fSuppress)
{
SYSTEMTIME st ;

GetLocalTime (&st) ;

if (f24Hour)
DisplayTwoDigits (hdc, st.wHour, fSuppress) ;
else
DisplayTwoDigits (hdc, (st.wHour %= 12) ? st.wHour : 12, fSuppress) ;

DisplayColon (hdc) ;
DisplayTwoDigits (hdc, st.wMinute, FALSE) ;
DisplayColon (hdc) ;
DisplayTwoDigits (hdc, st.wSecond, FALSE) ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static BOOL f24Hour, fSuppress ;
static HBRUSH hBrushRed ;
static int cxClient, cyClient ;
HDC hdc ;
PAINTSTRUCT ps ;
TCHAR szBuffer [2] ;

switch (message)
{
case WM_CREATE:
hBrushRed = CreateSolidBrush (RGB (255, 0, 0)) ;
SetTimer (hwnd, ID_TIMER, 1000, NULL) ;

// fall through

case WM_SETTINGCHANGE:
GetLocaleInfo (LOCALE_USER_DEFAULT, LOCALE_ITIME, szBuffer, 2) ;
f24Hour = (szBuffer[0] == '1') ;

GetLocaleInfo (LOCALE_USER_DEFAULT, LOCALE_ITLZERO, szBuffer, 2) ;
fSuppress = (szBuffer[0] == '0') ;

InvalidateRect (hwnd, NULL, TRUE) ;
return 0 ;

case WM_SIZE:
cxClient = LOWORD (lParam) ;
cyClient = HIWORD (lParam) ;
return 0 ;

case WM_TIMER:
InvalidateRect (hwnd, NULL, TRUE) ;
return 0 ;

case WM_PAINT:
hdc = BeginPaint (hwnd, &ps) ;

SetMapMode (hdc, MM_ANISOTROPIC) ;
SetWindowExtEx (hdc, 276, 72, NULL) ;
SetViewportExtEx (hdc, cxClient, cyClient, NULL) ;

SetWindowOrgEx (hdc, 138, 36, NULL) ;
SetViewportOrgEx (hdc, cxClient / 2, cyClient / 2, NULL) ;
SelectObject (hdc, GetStockObject (NULL_PEN)) ;
SelectObject (hdc, hBrushRed) ;

DisplayTime (hdc, f24Hour, fSuppress) ;

EndPaint (hwnd, &ps) ;
return 0 ;

case WM_DESTROY:
KillTimer (hwnd, ID_TIMER) ;
DeleteObject (hBrushRed) ;
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}

Re: Could anyone help me to comment these code in detail?

ThatsAlok9-Dec-04 22:12

ThatsAlok

9-Dec-04 22:12

case WM_PAINT:

	hdc = BeginPaint (hwnd, &ps) ;
	// i have removed though thing for beginner from here
	
	SelectObject (hdc, GetStockObject (NULL_PEN)) ;
	//simple it has selected the Red Brush for
	//to display digit
	SelectObject (hdc, hBrushRed) ;
	//Displaying time
	DisplayTime (hdc, f24Hour, fSuppress) ;
	
	EndPaint (hwnd, &ps) ;
return 0 ;

-----------------------------
"I Think this Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk

Re: Could anyone help me to comment these code in detail?

LiYS9-Dec-04 22:15

LiYS

9-Dec-04 22:15

/*What I mean is the following code, could you explain that in deepth?thanks!*/

SetMapMode (hdc, MM_ANISOTROPIC) ;
SetWindowExtEx (hdc, 276, 72, NULL) ;
SetViewportExtEx (hdc, cxClient, cyClient, NULL) ;

SetWindowOrgEx (hdc, 138, 36, NULL) ;
SetViewportOrgEx (hdc, cxClient / 2, cyClient / 2, NULL) ;

Re: Could anyone help me to comment these code in detail?

Mircea Puiu10-Dec-04 0:29

Mircea Puiu

10-Dec-04 0:29

Have a look at:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdi/metafile_0lwy.asp[^]

SkyWalker

Problem about Owner Window

Arcrest9-Dec-04 21:21

Arcrest

9-Dec-04 21:21

Hi, everyone.
in my dialog-based application, i want to create a dialog (CMyDialog) that is not owned by the main dialog. i derive a class named CMyThread from CWinThread and create an instance of CMyDialog(modaless dialog) in the InitInstance because i want an instance of CMyDialog has its own message loop, so i create instances of CMyDialog use this function:
CreateMyDialog()
{
AfxBeginThread(RUNTIME_CLASS(CMyThread));
}

if i call CreateMyDialog before the creation of main dialog ,then the dialog will not be owned by main dialog, of course, Smile | :)

. but if i call CreateMyDialog after the main dialog has been created, the dialog will be an owned window.

so how to create an instance of CMyDialog without an owner window after the main dialog has been created.

Thanks.

Forward key to another controller

Mathias S.9-Dec-04 21:11

Mathias S.

9-Dec-04 21:11

In a dialog I got a CEdit and a ListCtrl. And when I press any A-Z key in the ListCtrl I want that key to be forwarded to the edit controller and focus to be change so that continues writing will be in the CEdit.

The solution I came up with is this. It appears to work.
But I get a bad felling about this solution. Anyone know if this is a correct way of doing this

// m_pEdit is a pointer to the CEdit.
void CMyListCtrl::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags)
{
	if( nChar >= 'a'&& nChar <= 'z' || nChar >= 'A'&& nChar <= 'Z')
	{
		m_pEdit->PostMessage( WM_CHAR , (WCHAR)nChar,MAKELPARAM(nRepCnt,nFlags) );
		m_pEdit->SetFocus();
		return;
	}
	CListCtrl::OnChar(nChar, nRepCnt, nFlags);
}

Or should I do this from OnKeyDown instead?

/Mathias S.

Instance of a class.....

aaadetos9-Dec-04 20:44

aaadetos

9-Dec-04 20:44

I have a problem with an instance of a class. The class member variable instantiated by a class object appears not to be updated to what the user defines at run time.

The problem is to do with the fact that the user-defined variable at run-time is not being used. How do I change that. UpdateData(TRUE); in the change or update events of those variables don't work.

For instance,

<br />
double x = 0;//this is already initialized in the compiler-generated constructor <br />
<br />
CKuchukDlg MyClass;<br />
MyClass.m_dWellRad = x;<br />

At run-time, the proigram crashes. On debugging, I found that the compiler isn't using the value ascribed by the user(me) as x. After using x=0, x later becomes some bogus number: -9.2559631349318e+061. When i don't initialize my variable x, i get a warning; but still at run-time, x becomes this bogus number again, not the value set at run-time.

How can i capture the value set at run-time??

<br />
void CKuchukDlg::OnUpdateWellrad() <br />
UpdateData(TRUE);<br />

doesn't help. Neither does it help on the event-->void CKuchukDlg::OnChangeWellrad()

How to get WM_VSCROLL?

freehawk9-Dec-04 20:27

freehawk

9-Dec-04 20:27

Hello everyone

I have a window with two scrolls, and I want to get WM_VSCROLL in function "PreTranslateMessage(MSG* pMsg) ". Though I add "case WM_VSCROLL:" to soource code, but I can not get it. Because the message does not come into "PreTranslateMessage(MSG* pMsg)". How to get it?

Thanks.

-Freehawk

Re: How to get WM_VSCROLL?

ThatsAlok9-Dec-04 21:46

ThatsAlok

9-Dec-04 21:46

Overide WM_VSCROLL message in your Window
if you are using the MFC
the Function Declaration is like this

OnHScroll(UINT nSBCode,UINT nPos,CScrollBar *pScrollBar)

where pScrollbar contain pointer to that Scrollbar if it is not Window Default Scrollbar.

In Win32
lParam contain the pointer to The Scrollbar you have to typecast that.

-----------------------------
"I Think this Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk

Re: How to get WM_VSCROLL?

freehawk9-Dec-04 22:00

freehawk

9-Dec-04 22:00

In fact I want to handle something before WM_VSCROLL happens. I dont know how to catch.

-Freehawk

Re: How to get WM_VSCROLL?

ThatsAlok9-Dec-04 23:54

ThatsAlok

9-Dec-04 23:54

Are you using switch case like this

switch(LOWORD(pMsg->message))

or using some other method

-----------------------------
"I Think this Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.