C / C++ / MFC

Re: How to convert CString to char[] in MFC?(Very Urgent............)

3-Mar-09 12:48

Thank you for fixing.
BTW: who the hell is 'Gary Wheeler'?
Big Grin | :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Gary R. Wheeler4-Mar-09 12:26

Gary R. Wheeler

4-Mar-09 12:26

Why, he's my mild-mannered alter ego, of course.

Software Zen: delete this;
Fold With Us![^]

Re: How to convert CString to char[] in MFC?(Very Urgent............)

David Crow3-Mar-09 3:11

David Crow

3-Mar-09 3:11

VuNic wrote:
strcpy(ch, (LPSTR)(LPCTSTR)cs);

Why the unnecessary casts?

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"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

Re: How to convert CString to char[] in MFC?(Very Urgent............)

Eytukan3-Mar-09 4:38

Eytukan

3-Mar-09 4:38

Valid question. Actually I typed my reply with a char* .

char* ch = (LPSTR)(LPCTSTR)cs;

But knew that's a bad example. So changed that to char[] & and put the example as copy-the-buffer but had left the LPSTR caste unremoved . LPSTR is not need actually in this case.

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Re: How to convert CString to char[] in MFC?(Very Urgent............)

David Crow3-Mar-09 4:42

David Crow

3-Mar-09 4:42

VuNic wrote:
LPSTR is not need actually in this case.

Neither cast is needed. Just use:

strcpy(ch, cs);

Re: How to convert CString to char[] in MFC?(Very Urgent............)

Eytukan3-Mar-09 4:47

Eytukan

3-Mar-09 4:47

Yes we've been discussing that it returns a const char by default. The reason why I used LPCTSTR is that I couldn't cast it straight to char*. As CString doesn't support non-const version. I'm stupid I didn't think before typing. So we don't need all these caste craps when you are copying the buffer.

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Efficiency question

yellowine2-Mar-09 10:39

yellowine

2-Mar-09 10:39

I have the following codes:

double Length0(double x1, double y1, double z1, double x2, double y2, double z2)
{
	double dx = x2 - x1;
	double dy = y2 - y1;
	double dz = z2 - z1;

	return (dx*dx + dy*dy + dz*dz);
}

double Length1(double x1, double y1, double z1, double x2, double y2, double z2)
{
	return ((x2 - x1)*(x2 - x1) + (y2 - y1)*(y2 - y1) + (z2 - z1)*(z2 - z1));
}

Assume all other conditions are the same, which one (Length0 or Length1) theoretically executes faster?

A bit explanation is highly appreciated.

Stuart Dootson2-Mar-09 10:46

Stuart Dootson

2-Mar-09 10:46

With optimisations on, both the same - common sub-expression elimination should reduce Length1 to the equivalent of Length0, except with the variables in registers rather than on the stack.

With optimisations off...probably Length0 is more efficient.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Maximilien2-Mar-09 13:31

Maximilien

2-Mar-09 13:31

probably negligible with modern compilers.

This signature was proudly tested on animals.

«_Superman_»2-Mar-09 17:15

«_Superman_»

2-Mar-09 17:15

Below is the assembly code generated by Visual Studio 2008 for both the functions.
The code was generated with full optimization.

?Length0@@YANNNNNNN@Z PROC

	fld	QWORD PTR _x2$[esp-4]
	fsub	QWORD PTR _x1$[esp-4]
	fld	QWORD PTR _y2$[esp-4]
	fsub	QWORD PTR _y1$[esp-4]
	fld	QWORD PTR _z2$[esp-4]
	fsub	QWORD PTR _z1$[esp-4]
	fld	ST(1)
	fmulp	ST(2), ST(0)
	fld	ST(2)
	fmulp	ST(3), ST(0)
	fxch	ST(1)
	faddp	ST(2), ST(0)
	fmul	ST(0), ST(0)
	faddp	ST(1), ST(0)

	ret	0
	
?Length0@@YANNNNNNN@Z ENDP

?Length1@@YANNNNNNN@Z PROC

	fld	QWORD PTR _x2$[esp-4]
	fsub	QWORD PTR _x1$[esp-4]
	fld	QWORD PTR _y2$[esp-4]
	fsub	QWORD PTR _y1$[esp-4]
	fld	QWORD PTR _z2$[esp-4]
	fsub	QWORD PTR _z1$[esp-4]
	fld	ST(1)
	fmulp	ST(2), ST(0)
	fld	ST(2)
	fmulp	ST(3), ST(0)
	fxch	ST(1)
	faddp	ST(2), ST(0)
	fmul	ST(0), ST(0)
	faddp	ST(1), ST(0)

	ret	0
	
?Length1@@YANNNNNNN@Z ENDP

Here you will notice that both are exactly the same.
The compiler has taken away the responsibility from the programmer about optimizing code. At least a lot of it. Smile | :)

«_Superman_»
I love work. It gives me something to do between weekends.

Replacing contents of a file

Eytukan2-Mar-09 20:17

Eytukan

2-Mar-09 20:17

yellowine wrote:
double Length0(double x1, double y1, double z1, double x2, double y2, double z2)
{
double dx = x2 - x1;
double dy = y2 - y1;
double dz = z2 - z1;

return (dx*dx + dy*dy + dz*dz);
}

You can see no specific improvements with that change there. but on the other hand There would be some improvements with the first case (length0), If the calculations happen inside a loop. just a rough example:

double y1, double z1, double x2, double y2, double z2)
{
double dx = x2 - x1;
double dy = y2 - y1;
double dz = z2 - z1;

double result =0.0;

for(int i=xx;i<yx;i++)>
{
   result +=  (dx* i + dy * i + dz * i);
}
return result;
}

There it would make sense to keep them out of the loop and see some performance improvements.

He never answers anyone who replies to him. I've taken to calling him a retard, which is not fair to retards everywhere.-Christian Graus

Neelesh K J Jain2-Mar-09 9:58

Neelesh K J Jain

2-Mar-09 9:58

Hello Everybody,
I have a file Abc.txt with the following contents

Testing

]]>

In the above contents, I have to replace only the "cdef" present in the starting of the file, with some numbers say "1234". I couldn't able to do it using the CFile class. I have done a alternative way, by reading the contents and replacing the word and then re-create the file with the same name. I don't want to recreate the file instead I have to replace the string. Please help in solving this issue.

Thanks,
Neelesh K J Jain.

Re: Replacing contents of a file

CPallini2-Mar-09 10:09

Re: Replacing contents of a file

2-Mar-09 10:09

No cookie for you: you've just found the only viable solution and discarded it badly.
Smile | :)

Rajesh R Subramanian2-Mar-09 19:53

Rajesh R Subramanian

2-Mar-09 19:53

CPallini wrote:
No cookie for you: you've just found the only viable solution and discarded it badly.

I'm proposing this for the most memorable quotes of CP for this year.

It is a crappy thing, but it's life -^ Carlo Pallini

Re: Replacing contents of a file

CPallini2-Mar-09 21:18

OnAppExit not called when X button clicked

2-Mar-09 21:18

Well,to be included, the sentence must be really memorable, I suppose the OP should try harder, the next time.. Roll eyes | :rolleyes:

TimmySRX2-Mar-09 9:49

TimmySRX

2-Mar-09 9:49

I have a multi-tabbed app that on exit is trying to override the OnAppExit() function to call a bit of house claening code so that I don't have a memory leak. My problem is that if I use the file->menu->exit route it will call the OnAppExit() function and I can call my function to house clean. But if I close by using the X in the upper right pane it never calls the exit function and a leak occurs. I have tried all I know to figure out why but am lost so here I am. I am fairly green to MFC so any tips or help would be appreiceated. The code that I have done is:

void CdatamaxApp::OnAppExit()
{
if( IsOnline() == TRUE )
{
int nRetValue;
nRetValue = MessageBox( NULL,"Still ONLINE, YES to Quit, NO returns to App", TEXT("Datamax Exit"), MB_ICONERROR|MB_YESNO );
if(nRetValue == IDYES)
{
OnGoOffline();
AfxGetMainWnd()->;PostMessage ( WM_CLOSE );
}
else
{

}
}
else
{
AfxGetMainWnd()->;PostMessage ( WM_CLOSE );
}
}

How can I debug or set a breakpoint to figure out why this function doesn't get called when I close app with the x close button vs using the file menu, don't they both issue the same event?

Re: OnAppExit not called when X button clicked

Stuart Dootson2-Mar-09 10:15

Stuart Dootson

2-Mar-09 10:15

You're probably best off overriding CWinApp's ExitInstance method? That should be called whatever (standard) mechanism you use to exit the application.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: OnAppExit not called when X button clicked

TimmySRX2-Mar-09 11:05

TimmySRX

2-Mar-09 11:05

Thanks for the feedback, it does work to call ExitInstance(). I think the answer is yes but I no longer need to post message to WM_CLOSE window as I was doing before, it workS without the call but just wanted to make sure that nothing else is needed inside the ExitInstance when it is called other than my own code.

Re: OnAppExit not called when X button clicked

Iain Clarke, Warrior Programmer2-Mar-09 23:04

Iain Clarke, Warrior Programmer

2-Mar-09 23:04

TimmySRX wrote:
but just wanted to make sure that nothing else is needed inside the ExitInstance

Then call the base implementation also. It's the only way to be sure.

This code is taken from the documentation for ExitInstance (You do read those, I hope?)

// MySampleApp.cpp.

int CMySampleApp::ExitInstance() 
{
   // TODO: Add your specialized code here and/or
   // call the base class.

   if ( m_pMySampleMem )
      delete m_pMySampleMem;
   
   DoCleanup();

   return CWinApp::ExitInstance();                        // <---- Note the call to the base implementation
}

This is good practise for any MFC thing you override. You don't always want to do it, but you should make a conscious decision about it.

Iain.

Codeproject MVP for C++, I can't believe it's for my lounge posts...

SendKeys won't work

Ran42-Mar-09 8:49

Ran4

2-Mar-09 8:49

(I've now spent the last 2½ hours trying to get this to work. I've read something like 60 pages on google.).

I'm trying to get the SendKeys for C++ to work, but to no avail.
I have tried what I think is all possible variations of SendKeys.h, windows.h, StdAfx.h and "#define _WIN32_WINNT 0x0501" (I have seen 0x0501, 500, 400, 401, 503, 510... Everyone says that what they say work. Well... no.). I simply cannot include that INPUT object (error C2065: 'INPUT' : undeclared identifier).

I am quite certain that all I need is to have ~5 rows of code in the right place. Which are these codes, and in which order should they be?

I'm using Visual C++ 6.0 (I also have the 2008 version available) with Windows XP SP2.

Now, I suppose you are supposed to do something like this:
1. Create a win32 project in visual c++ 6.0
2. Add a main.cpp file which has the main function in it
3. Add the SendKeys.cpp, StdAfk.cpp, SendKeys.h, StdAfx.h and resource.h files to the project (right-click -> add files to folder?)
4. Write something weird at the very beginning of StdAfx.h
5. Include the right things in my main.cpp
6. Create the main function, then create a CSendKeys object and then use it
7... here on, I could probably follow the official guide.

Which of the above is wrong?

led mike2-Mar-09 9:49

led mike

2-Mar-09 9:49

Ran4 wrote:
4. Write something weird at the very beginning of StdAfx.h

ROTFLMAO Yeah that's the technical term for it! Laugh | :laugh:

Ran4 wrote:
Which of the above is wrong?

You are, you're the one that's wrong. You apparently believe you should be able to create software without actually knowing what you are doing. I hope you don't find yourself in the hands of some surgeon that thinks the same way.

Ran42-Mar-09 10:14

Ran4

2-Mar-09 10:14

Huh? What are you talking about? What do you get out of being rude?
I want to create a program, something is in the way of that (this problem), and this is a place where I can hopefully learn how to do it. Learning your compiler is nearly impossible without someone helping you, as you know yourself.

CPallini2-Mar-09 10:19

2-Mar-09 10:19

Well, I should admit: learning led mike's compiler is troublesome... Roll eyes | :rolleyes:

modified on Monday, March 2, 2009 4:28 PM

«_Superman_»2-Mar-09 17:33

«_Superman_»

2-Mar-09 17:33

SendKeys is for the .Net platform.
You should be using SendInput.

«_Superman_»
I love work. It gives me something to do between weekends.