Re: Unhandled exception when writing to allocated memory. - C / C++ / MFC Discussion Boards

Re: How do i pass a function to a function that need a DWORD?

Stephane Rodriguez.12-Sep-02 9:38

12-Sep-02 9:38

If you compile this on a WIN32 system, DWORD_PTR is an unsigned long.
(and it's __int64 if you compile using WIN64, which is 8-byte).

See <basetsd.h>

MS quote (http://www.microsoft.com/ddk) : As of September 30, 2002, the Microsoft® Windows® 2000 DDK, the Microsoft Windows 98 DDK, and the Microsoft Windows NT® 4.0 DDK will no longer be available for purchase or download on this site. Support for development will ship at the same time as the Windows XP Service Pack 1 (SP1) release.

index of selected item in listctrl

danag12-Sep-02 8:56

danag

12-Sep-02 8:56

How do i get the index of the selected item in list control?

Re: index of selected item in listctrl

Tomasz Sowinski12-Sep-02 9:05

Tomasz Sowinski

12-Sep-02 9:05

int itemIndex = m_lstFoo.GetNextItem(-1, LVNI_SELECTED);

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

Re: index of selected item in listctrl

danag12-Sep-02 9:17

danag

12-Sep-02 9:17

Thanks, I am able to get the index.
I have 1 more Qs.
I have written an message hanler for the list control for the message LVN_ENDLABELEDIT.
After i edit the selected field , I want to put the newly typed data in it. So, i tried to use the listctrl.GetNextItem();
listctrl.GetItemText(); --- But this fucntion has the original text & not the new text
and listctrl.SetItemText().

Re: index of selected item in listctrl

Tomasz Sowinski12-Sep-02 9:23

Tomasz Sowinski

12-Sep-02 9:23

All you need to set the item text in LVN_ENDLABELEDIT handler is to return TRUE. If you're using MFC, then you need to set *pResult to TRUE.

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

Re: index of selected item in listctrl

danag12-Sep-02 9:24

danag

12-Sep-02 9:24

THANKS. I GOT IT.

Unhandled exception when writing to allocated memory.

12-Sep-02 8:26

BYTE *sSourceBuffer;
DWORD dwSourceBufferSize = 176400;

sSourceBuffer = (BYTE *)LocalAlloc(LMEM_MOVEABLE | LMEM_ZEROINIT, dwSourceBufferSize);
memset(sSourceBuffer, 0, dwSourceBufferSize);

When i get to the memset line i get an unhandled exception message;
Unhandled exception at 0x00414085 in MP3.exe: 0xC0000005: Access violation writing location 0x00911000.
And i jumps to some asm code:

; Set dword-sized blocks
        mov     ecx,edx         ; move original count to ecx
        and     edx,3           ; prepare in edx byte count (for tail loop)
        shr     ecx,2           ; adjust ecx to be dword count
        jz      tail            ; jump if it was less then 4 bytes

        rep     stosd   <----- CURSOR IS HERE

Here's the values of the different variables:

ecx = 43079
edx = 0
tail = 0x0041408b tail

(From the command window)

Anyone know what could be wrong?

Thanks in advance.

Re: Unhandled exception when writing to allocated memory.

Tomasz Sowinski12-Sep-02 8:43

Tomasz Sowinski

12-Sep-02 8:43

Are you sure LocalAlloc call succeeds?

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

Re: Unhandled exception when writing to allocated memory.

Redeemer-dk12-Sep-02 8:53

Redeemer-dk

12-Sep-02 8:53

The function returns a valid handle to a piece of memory and not NULL, so it should have succeeded, BUT, i've found out that the when i allocate two pieces of memory after each other (which is what i do in my program) the second allocation is only 8 bytes away from the first one.

sSourceBuffer = (BYTE *)LocalAlloc(LMEM_MOVEABLE | LMEM_ZEROINIT, dwSourceBufferSize);
sDestBuffer = (BYTE *)LocalAlloc(LMEM_MOVEABLE | LMEM_ZEROINIT, dwDestBufferSize);

The first one gets the address 0x0091000c and the seconds gets 0x00910014. What could be wrong here?

BTW, at runetime the dwDestBufferSize is 73599, and the dwSourceBufferSize is 176400.

Thanks.

Re: Unhandled exception when writing to allocated memory.

TyMatthews12-Sep-02 8:52

TyMatthews

12-Sep-02 8:52

LocalAlloc() does not return a pointer, it returns a handle, aka HLOCAL. Your memset fails because the address you're sending is not really an address at all. In order to translate that HLOCAL into a valid pointer to physical memory, call LocalLock(). LocalLock will return an actual pointer to physical memory which you can then use. BTW, you wouldn't have to call memset there and initialize the buffer to zero, since you're specifying LMEM_ZEROINIT in the call to LocalAlloc()... it's redundant Smile | :)

DWORD dwBufferSize = 176400;
HLOCAL hBuffer = NULL;
LPVOID lpBuffer = NULL;

__try
{
   hBuffer = LocalAlloc( LMEM_MOVEABLE | LMEM_ZEROINIT, dwBufferSize );
   if( hBuffer )
   {
      lpBuffer = LocalLock( hBuffer );

      if( lpBuffer )
      {
          // Do some stuff with the pointer
      }
   }
}
__finally
{
   if( hBuffer )
   {
      LocalUnlock( hBuffer );
      LocalFree( hBuffer );
   }
}

</code>

Re: Unhandled exception when writing to allocated memory.

Joaquín M López Muñoz12-Sep-02 8:53

Joaquín M López Muñoz

12-Sep-02 8:53

By specifying LMEM_MOVEABLE, LocalAlloc is not returning a pointer to memory, but a handle. Either use LMEM_FIXED instead, or use LocalLock to convert the handle to an actual pointer.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Thanks all, now i see :)

Anonymous12-Sep-02 9:01

Anonymous

12-Sep-02 9:01

Win2K and Multilink

Tili12-Sep-02 8:20

Tili

12-Sep-02 8:20

I developed a dialer which creates an entry in DUN but the problem is tht it can't disable multilink programatically. It doesnt work with my client as it doesnt connect to their ISP as long as multilink is enabled. It works on WinXP because it can disable multilink.

I dont want to disable it globally through registry. ANybody has any thought plz share it with me if it is gonna be helpful to me.

In my dream, I was dorwning my §orrow§
But my §orrow§, they learned to §wim

Still Dialog menu problems

DarrollWalsh12-Sep-02 8:10

DarrollWalsh

12-Sep-02 8:10

ok I have read a few post now so I know that you have to handle the WM_KICKIDLE message to be able manipulate menus in a dialog nased app. What I now need to know is do I update the menu in the menus UPDATE_COMMAND_UI or do I have to create a CMenu object and pull and manipulate the menu in a user function? If someone could give me ALL the code snipits they used or walk my dumb @$$ through this I would apreciate it.

Darroll

Not one person lives in the present. Only the past. I can prove it.

Re: Still Dialog menu problems

Tomasz Sowinski12-Sep-02 8:22

Tomasz Sowinski

12-Sep-02 8:22

You can find all code snippets you need to walk your dumb@$$ through this in DLGCBR32 MFC sample (which comes with VC++).

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

Re: Still Dialog menu problems

DarrollWalsh12-Sep-02 8:42

DarrollWalsh

12-Sep-02 8:42

OK I soent some time looking through the code and still no. I now understand why just UPDATE_COMMAND_UI fails, it doesn't get a pointer to the dialog. Stupid MFC. SO I need to pass OnUpdateCmdUI the pointer to my dialog. But, sorry, I am new and this doesn't give me everything I need. How do I set up my app to call OnUpdateCmdUI() It gives me a not found error. I cannot find it in the Class wiz. I probably need to create it in the message map myself, but I wanted to ask.

Still a Dumb @$$
Darroll

Not one person lives in the present. Only the past. I can prove it.

Re: Still Dialog menu problems

Tomasz Sowinski12-Sep-02 8:47

Tomasz Sowinski

12-Sep-02 8:47

The KB article Q242577 'PRB: Update Command UI Handlers Do Not Work for Menu Attached to a Dialog Box' may help.

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

Re: Still Dialog menu problems

DarrollWalsh12-Sep-02 8:56

DarrollWalsh

12-Sep-02 8:56

Tomasz I could kiss you. Why others could not reference this I don't know. This is EXACTLY what I was looking for. I guess I should start looking into thouse KB articles. THANK YOU SO MUCH!!!

Not so much of a Dumb @$$ anymore

Darroll

PS.
I am not really going to kiss you so don't get to excited. Poke tongue | ;-P

Not one person lives in the present. Only the past. I can prove it.

Re: Still Dialog menu problems

Tomasz Sowinski12-Sep-02 9:06

Tomasz Sowinski

12-Sep-02 9:06

darroll wrote:
I am not really going to kiss you so don't get to excited

Without the photo in your profile I didn't get excited anyway Poke tongue | ;-P

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

Re: Still Dialog menu problems

DarrollWalsh12-Sep-02 9:24

DarrollWalsh

12-Sep-02 9:24

I still hope you don't get excited but I posted my pic in my profile.

Not one person lives in the present. Only the past. I can prove it.

Re: Still Dialog menu problems

Tomasz Sowinski12-Sep-02 9:28

Tomasz Sowinski

12-Sep-02 9:28

darroll wrote:
I still hope you don't get excited

I don't. Big Grin | :-D

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

height of title bar of modeless CDialog

ns12-Sep-02 8:09

12-Sep-02 8:09

Is it possible to get the height of the titlebar of a modeless CDialog? I have this code currently which fits the CDialog exactly into my ImageBox. I want it to fit such that the client area has the exact fit to the imagebox, and the titlebar extends above.

    CRect picRect;

    m_THBImage6.GetWindowRect(&picRect);

pdlg0->SetWindowPos(&CWnd::wndNoTopMost,picRect.left,picRect.top,picRect.Width(),picRect.Height(),SWP_SHOWWINDOW );
pdlg0->ShowWindow(SW_SHOW);

MSDN doesnt say, but does Width() return the number of pixels? In that case, I'd need to know the titlebar height in pixels too. I am thinking that the new code to do what I want would be:

    CRect picRect;

    m_THBImage6.GetWindowRect(&picRect);


pdlg0->SetWindowPos(&CWnd::wndNoTopMost,picRect.left,picRect.top,picRect.Width(),<code>picRect.Height()+ titleBarHeight</code>,SWP_SHOWWINDOW );
pdlg0->ShowWindow(SW_SHOW);

Re: height of title bar of modeless CDialog

Tomasz Sowinski12-Sep-02 8:19

Tomasz Sowinski

12-Sep-02 8:19

Use AdjustWindowRect[Ex].

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

Handle WM in CDialog derived class

Ludovic Balogh12-Sep-02 7:56

Ludovic Balogh

12-Sep-02 7:56

Simple and stupid question : I want to handle WM_HOTKEY in my CDialog dervied class, but I don't know how to do this ??

Re: Handle WM in CDialog derived class

Tomasz Sowinski12-Sep-02 8:17

Tomasz Sowinski

12-Sep-02 8:17

You'll have to add handler/message map entry (ON_MESSAGE) manually. Check ON_MESSAGE docs for more info.

Tomasz Sowinski -- http://www.shooltz.com

To some its a six-pack, to me it's a support group

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