C / C++ / MFC Discussion Boards

Re: an interview question

qudayong5-Jul-05 15:14

qudayong

5-Jul-05 15:14

Thank you. You opinion ia valuable

Re: an interview question of undo/redo

C^hris L^osinger5-Jul-05 15:27

C^hris L^osinger

5-Jul-05 15:27

for text, it's pretty easy:

when the user performs an action, save the action in a stack, then perform the action on the document. for undo, pop the last action off the stack and reverse the action.

the trick is to define 'action' in such a way that you can undo it.

ex. for deleting text, save the deleted text and its position as the action (to undo, insert the deleted text at the position). for inserting text, save the position and the number of characters added (to undo, remove the number of characters at the position).

Cleek | Image Toolkits | Thumbnail maker

Re: an interview question of undo/redo

qudayong6-Jul-05 1:59

qudayong

6-Jul-05 1:59

Suppose you have 20 pages file.
You last action is delete 19 pages, and the perform undo. If you perform this action servral times, your stack will be overloaded.

Re: an interview question of undo/redo

C^hris L^osinger6-Jul-05 2:13

C^hris L^osinger

6-Jul-05 2:13

that's why programs put up messages like "Insufficient space in the Undo buffer to save this action. Do you wish to proceed anyway?" (from the Visual Studio editor)

Cleek | Image Toolkits | Thumbnail maker

Re: an interview question of undo/redo

Mister Transistor14-Jul-05 3:30

Mister Transistor

14-Jul-05 3:30

that's not usually true - you can't undo an undo - when you do the first undo, the stack is emptied

Re: an interview question of undo/redo

qudayong6-Jul-05 4:34

qudayong

6-Jul-05 4:34

Having a test on MS-WORD, I find that you delete 20 page then perform undo. After 30 times there's no complain about memory and the action performs very fast. So I assume, there must has other way than "command pattern" to perform such an action.

cheers

Re: HELP VC++ my program is stuck.

Wes Aday5-Jul-05 7:51

Wes Aday

5-Jul-05 7:51

I might as well say it before the flaming starts.... if you have a specific question to ask, I am sure that someone here would be more than happy to help.... The first thing you will hear is "do your own homework"...

So why can't YOU get it to run in VC++?

Artificial intelligence is no match for natural
stupidity.

Never argue with an idiot. They will drag you down to their level where they are an expert.

Re: HELP VC++ my program is stuck.

Anonymous5-Jul-05 8:44

Anonymous

5-Jul-05 8:44

My VC++6 & MS DEV is somewhat out of order, I tried to re-load but was unsuccessful; I need to change the TEST file html code so that the student name and # appears beneath the clock; if I do and try to save it I get just under 20 errors when I attempt to run(!); I am supposed to copy and paste the TEST html code to Notepad or Wordpad, save as html to a deskcop icon; html code to change and save:

ERROR

Betty Hope<h 2=""> ERROR

898654712<h 2=""> ERROR

Betty Hope

898654712

ALSO WINZIPPED it and another friend could not unzip it properly to have a look. thanks for any help.

How to execute a file in memory being of type CMemFile

Anonymous5-Jul-05 7:15

Anonymous

5-Jul-05 7:15

I have created an executive file in the form of CMemFile In an MFC application, which is directly copied in memory and is not on the hard disk. Now, how to execute this file directly from the memory? I tried to use the ShellExecute method, however, it does not accept the CMemFile giving an error saying that it cannot convert CMemFile to LPCSTR.

Is there any method to directly execute the exe file from the memory?

Regards

Re: How to execute a file in memory being of type CMemFile

David Spain5-Jul-05 17:56

David Spain

5-Jul-05 17:56

How does CMemFile store its data? Most likely it stores a pointer to the memory that contains the actual data. Look in the Microsoft documentation for CMemFile to see how it stores the data. Hopefully, CMemFile has a method to provide this pointer. An LPCSTR is a pointer to a string, so method could be called and the result could be cast to an LPCSTR if it is not already returned that way. Then this could be provided to the ShellExecute function.

David Spain, C++ Applications Programmer

Re: How to execute a file in memory being of type CMemFile

Jose Lamas Rios5-Jul-05 18:25

Jose Lamas Rios

5-Jul-05 18:25

David Spain wrote:
How does CMemFile store its data? Most likely it stores a pointer to the memory that contains the actual data. Look in the Microsoft documentation for CMemFile to see how it stores the data. Hopefully, CMemFile has a method to provide this pointer. An LPCSTR is a pointer to a string, so method could be called and the result could be cast to an LPCSTR if it is not already returned that way. Then this could be provided to the ShellExecute function.

I don't think so. You might obtain the CMemFile data using Detach, which returns a BYTE* and also closes the file. The return type is a BYTE* because a file may contain any type of data, not just text. Casting it to an LPCTSTR makes no sense: it may fool the compiler into accepting it, but the content will still be the same, and if it wasn't text, no one interpreting it as such will have correct results. In this case, in fact, it's an executable (binary) file.

Besides, ShellExecute expects to receive the name of the file path and name, not the content of the file.

--
jlr
http://jlamas.blogspot.com/[^]

Re: How to execute a file in memory being of type CMemFile

David Spain5-Jul-05 19:10

David Spain

5-Jul-05 19:10

Jose Lamas Rios wrote:
I don't think so. You might obtain the CMemFile data using Detach, which returns a BYTE* and also closes the file. The return type is a BYTE* because a file may contain any type of data, not just text. Casting it to an LPCTSTR makes no sense: it may fool the compiler into accepting it, but the content will still be the same, and if it wasn't text, no one interpreting it as such will have correct results. In this case, in fact, it's an executable (binary) file.

You are right. What I wrote actually made no sense. Obviously the ShellExecute function wants a string pointer, that points to the name of an actual file on disk.

As simply another idea, an executable in memory seems similar to a running process. Would using CreateProcess or something similar be a better avenue to pursue instead of ShellExecute?

David Spain, C++ Applications Programmer

Proxy authentication

Geert van Horrik5-Jul-05 6:04

Geert van Horrik

5-Jul-05 6:04

Hi all,

I need to authenticate myself to a proxy. I have the domain\username and password.

I set it like this:

<br />
		InternetSetOption((HINTERNET)(*pHttpFile), INTERNET_OPTION_USERNAME, <br />
						  sUsername, sUsername.GetLength());<br />
		InternetSetOption((HINTERNET)(*pHttpFile), INTERNET_OPTION_PASSWORD, <br />
						  sPassword, sPassword.GetLength());

However, I still get the 407 error code.

Any idea how to set username and password for a file when behind a proxy?

Thanks!

Geert

Want to spread the newest version of your software automatically? Use Updater!
Visit my website: www.gvhsoftware.org

Rebar controls

__makaveli__5-Jul-05 5:36

__makaveli__

5-Jul-05 5:36

I am trying to get a rebar added to an existing MDI window, I am using the following code:

<br />
INITCOMMONCONTROLSEX icex;<br />
<br />
icex.dwSize = sizeof(INITCOMMONCONTROLSEX);<br />
icex.dwICC   = ICC_COOL_CLASSES|ICC_BAR_CLASSES;<br />
InitCommonControlsEx(&icex);<br />
<br />
HINSTANCE hInst = (HINSTANCE)GetWindowLong(hParentHandle, GWL_HINSTANCE);<br />
hToolbar = CreateWindowEx(WS_EX_TOOLWINDOW,REBARCLASSNAME,NULL,WS_VISIBLE | WS_BORDER | WS_CHILD | WS_CLIPCHILDREN | WS_CLIPSIBLINGS | RBS_VARHEIGHT | RBS_BANDBORDERS | CCS_NODIVIDER | CCS_NOPARENTALIGN,0,0,0,0,hParentHandle,NULL,hInst,NULL);<br />
if( !hToolbar ) {<br />
	MessageBox(0, "Could not create toolbar control", "Error", MB_OK | MB_ICONHAND);<br />
	return;<br />
}<br />
<br />
SetWindowLong(hWndBar, GWL_STYLE, WS_VISIBLE | WS_CHILD | TBSTYLE_TOOLTIPS | CCS_NOPARENTALIGN | CCS_NORESIZE);<br />
SetWindowPos(hWndBar, 0, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);<br />
<br />
RECT rect;<br />
GetWindowRect (hWndBar, &rect);<br />
<br />
REBARINFO rbi;<br />
rbi.cbSize = sizeof(REBARINFO);<br />
rbi.fMask = NULL;<br />
SendMessage(hToolbar, RB_SETBARINFO, 0, (LPARAM)&rbi);<br />
<br />
REBARBANDINFO rbb;<br />
rbb.cbSize = sizeof(REBARBANDINFO);<br />
rbb.fMask = RBBIM_SIZE | RBBIM_CHILD | RBBIM_CHILDSIZE | RBBIM_ID | RBBIM_STYLE | RBBIM_TEXT | 0;<br />
rbb.hwndChild = hWndBar;<br />
rbb.cxMinChild = rect.right - rect.left + 2;<br />
rbb.cyMinChild = rect.bottom - rect.top + 2;<br />
rbb.cx = 250;<br />
rbb.fStyle = RBBS_BREAK | RBBS_GRIPPERALWAYS;<br />
rbb.wID = 100085;<br />
rbb.lpText = TEXT("Toolbar");<br />
<br />
// Add the band that has the combo box.<br />
SendMessage(hToolbar, RB_SETPARENT, (WPARAM) (HWND) data->hParentHandle, (LPARAM)0);<br />
SendMessage(hToolbar, RB_INSERTBAND, (WPARAM)-1, (LPARAM)&rbb);<br />
SendMessage(hToolbar, RB_SHOWBAND, (WPARAM)(UINT)0, (LPARAM)(BOOL)TRUE);<br />
SetWindowPos(hToolbar, 0, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);<br />

Now using that code, the bar appears to flash on the screen but doesn't stay there, what am I missing?

how to protect dll from replacement.

Abdul Munaf Chhatra5-Jul-05 3:26

Abdul Munaf Chhatra

5-Jul-05 3:26

Hi,

I have one executable say program.exe which is linked with first.dll.
first.dll contains TestClass. Now if i replace the first.dll with the
dll of same name and same exported function of class TestClass, but
having different implimentation, then the program.exe is executed with
replaced first.dll.

Is there any way to know that the first.dll is replaced or not.

Regards

AbdulMunaf Chhatra
Software Engineer,
C-Sam Solutions Pvt. Ltd.
Phone : +91-265-2324018/19
Email : a.chhatra@popnet.co.in

Re: how to protect dll from replacement.

David Crow5-Jul-05 3:43

David Crow

5-Jul-05 3:43

Abdul Munaf Chhatra wrote:
Is there any way to know that the first.dll is replaced or not.

How about looking for an exported function or global variable that exists only in the original DLL?

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Re: how to protect dll from replacement.

«_Superman_»5-Jul-05 4:01

«_Superman_»

5-Jul-05 4:01

Here is something I did a long ago.

Create a global string in the DLL like

char* pCpde = "My Secret Code";

Before loading the DLL from the EXE, open the DLL in binay mode from the EXE.
Search for your secret code.

If it exists, close the DLL file and load it.

I call it signing code. Poke tongue | ;-P

« Superman »

MS Word View->Print-Layout code?

Maverick5-Jul-05 3:10

Maverick

5-Jul-05 3:10

If you look at MS Word, with a new blank document.. and then choose View->Print Layout menu.. Now, you'll see the white page on the brown/gray background.. on a 100% view

I know that on normal circumstances in Doc/View architecture, the client area of CView entirely occupies the client area of the CCHildFrame..

Now with the Print-Layout View, Is it possible that the white page is drawn on the CView client area but it is NOT occupying the whole client area of CCHIldFrame so thats why we are seeing the background color of CChildFrame?

Or is the white page and the background color are all drawn together in the client area of CView?

Maverick

"watch the birdie!..."

Re: MS Word View->Print-Layout code?

Chris Meech5-Jul-05 6:33

Chris Meech

5-Jul-05 6:33

I used Spy++ and using the window finder tool suggests that the 'white paper' that you see is a window that is not part of the background that the paper 'sits' on.

I'd be surprised to learn that the MFC document/view classes are in use in Word.

Chris Meech

I am Canadian. [heard in a local bar]

Remember that in Texas, Gun Control is hitting what you aim at. [Richard Stringer]

Nice sig! [Tim Deveaux on Matt Newman's sig with a quote from me]

Re: MS Word View->Print-Layout code?

Maverick5-Jul-05 16:05

Maverick

5-Jul-05 16:05

so u're saying that Doc/View classes aren't used in Word?

Re: MS Word View->Print-Layout code?

Jose Lamas Rios5-Jul-05 17:45

Jose Lamas Rios

5-Jul-05 17:45

Maverick wrote:
so u're saying that Doc/View classes aren't used in Word?

Maybe they use some Doc/View classes, but most likely not MFC's CDocument and CView

--
jlr
http://jlamas.blogspot.com/[^]

CDialogBar and CMDIFrameWnd

__makaveli__5-Jul-05 2:16

__makaveli__

5-Jul-05 2:16

I am trying to create a CDialogBar from an existing window using the Attach() method (I have to use Attach because the window is created by a seperate process belonging to my app), I also have a CMDIFrameWnd which I would like to dock the dialog bar to, I am using this code:

<br />
data->m_pParent = new CMDIFrameWnd;<br />
if( !data->m_pParent->Attach(data->hParentHandle) ) {<br />
	ShowError();<br />
	return;<br />
} else {<br />
	MessageBox(0, "Attached OK", "Attach", MB_OK);<br />
}<br />
	<br />
SetWindowLong(hWndBar, GWL_STYLE, WS_CHILD | CBRS_LEFT | CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY);<br />
		<br />
data->m_pBar = new CDialogBar;<br />
if (!data->m_pBar->Attach(hWndBar) )<br />
{<br />
   ShowError();<br />
   return;<br />
}<br />
<br />
data->m_pBar->EnableDocking(CBRS_ALIGN_ANY);<br />
data->m_pParent->EnableDocking(CBRS_ALIGN_ANY);<br />

But I get a failed assertion on this line in dockcont.cpp

<br />
ASSERT(pBar->m_pDockSite != NULL);<br />

Am I even heading in the right direction here?

Thanks in advance

Question about class CSplitterWnd

PRJ15rf5-Jul-05 2:03

PRJ15rf

5-Jul-05 2:03

Hi,

I have code like in this manner to split the pane that will have 2 rows and 1 column.
VERIFY(m_wndSplitter.CreateStatic(this, 2, 1));

VERIFY(m_wndSplitter.CreateView(0, 0, RUNTIME_CLASS(SmallClass), CSize(100,100), pContext));
VERIFY(m_wndSplitter.CreateView(1, 0, RUNTIME_CLASS(BigClass), CSize(100,100), pContext));

This always displays two panes.
Now my task is to find out at run time and display only one pane, but when I changed the code
VERIFY(m_wndSplitter.CreateStatic(this, 1, 1));
I am getting an assertion stating that either maxCol or maxRow should be greater than 1 in winsplit.cpp.

Can somebody help me out to display one pane/ two panes and decide about this at run time?

Thanks,
PRJ

Re: Question about class CSplitterWnd

PJ Arends5-Jul-05 11:00

PJ Arends

5-Jul-05 11:00

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_mfc_csplitterwnd.asp[^]

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_mfcnotes_tn029.asp[^]

Read these articles in MSDN. Make sure you understand the differnce between CSplitterWnd::Create() and CSplitterWnd::CreateStatic(). Also look up CSplitterWnd::SetRowInfo and CSplitterWnd::SetColumnInfo.

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

"Obviously ??? You're definitely a superstar!!!" - mYkel - 21 Jun '04

"There's not enough blatant self-congratulatory backslapping in the world today..." - HumblePie - 21 Jun '05

Within you lies the power for good - Use it!

Toolbar

Anonymous5-Jul-05 1:25

Anonymous

5-Jul-05 1:25

i need to access the toolbar which is created in the parent window from the child window. but i m unable to do so. what should be done? can any1 pliz suggest.

thanx in advance

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