C / C++ / MFC Discussion Boards

GGConsulting19-Aug-04 6:07

19-Aug-04 6:07

I have a Problem with casting a CString to Char.

I made this Function

char * GetCommand(void)
{
return (char*)&this->m_sCommand;
}

m_sCommand is a CString and the calling class needs to get a pointer to a Char Array.

It doesn't work the way I made it. Its no Error, but silly Data.
I don't know, how big m_sCommand is, so it all has to by dynamic.
Does anybody understand my problem?
Please help me, if You can.
Greetings
Gerhard from Germany

Re: Make CString to char*

toxcct19-Aug-04 6:15

toxcct

19-Aug-04 6:15

<font style="color:blue;">char</font>* GetCommand(<font style="color:blue;">void</font>) {
    <font style="color:blue;">return</font> (LPCTSTR)<font style="color:blue;">this</font>->m_sCommand;
}

TOXCCT >>> GEII power

Re: Make CString to char*

GGConsulting19-Aug-04 7:57

GGConsulting

19-Aug-04 7:57

Thank you for quick answer.

I did it and got compiler error:
error C2440: 'return': 'ATL::CSimpleStringT<basetype,t_bmfcdll>::PCXSTR' kann nicht in 'char *' konvertiert werden

Try to translate:
error C2440: 'return': 'ATL::CSimpleStringT<basetype,t_bmfcdll>::PCXSTR' can not be convertete to 'char *'

What now?

Re: Make CString to char*

GGConsulting19-Aug-04 8:00

GGConsulting

19-Aug-04 8:00

But with
const char* GetCommand(void) {

return (LPCTSTR)this->m_sCommand;

}
it is working. Now I have tr test, where to change on other places.

Re: Make CString to char*

toxcct21-Aug-04 7:14

toxcct

21-Aug-04 7:14

yes, i didn't mentionned that the LPCTSTR type was a typedef of the const char* one.

sorry for my mistake.

TOXCCT >>> GEII power

Re: Make CString to char*

Chris Meech19-Aug-04 6:43

Chris Meech

19-Aug-04 6:43

You are taking the address of an instance of a CString and casting it to a char*. That will not work as you have discovered. If you use 'toxcct' response you should find that may work fine. What that response does is use CString's ability to convert itself to a char*. However the pointer you are given is a const pointer and you are then casting away the const'ness. As long as you do not try to change the buffer contents that the pointer points to, you will be fine. But if you need non-const access, you will need to code this differently. Probably through some kind of Set method.

Chris Meech

I am Canadian. [heard in a local bar]

I think people should be required to have an operator's permit to use the internet. John Simmons

I have a feeling that if the millions of man hours wasted every year by geeks trying to get various video and sound cards working under Linux were put into some useful endeavor we'd have solved world hunger, we'd have peace and aids would be no more. [JOS poster]

Re: Make CString to char*

BlackDice19-Aug-04 10:13

BlackDice

19-Aug-04 10:13

what about sprintf()?

[insert witty comment here]

bdiamond Sleepy | :zzz:

Re: Make CString to char*

Jeff Bogan19-Aug-04 15:20

Jeff Bogan

19-Aug-04 15:20

You should copy the data to buffer either supplied in the argument list or to a global buffer if you are not planning on doing anything extreme with it.

fShared Memory

Krishnan V19-Aug-04 5:37

Krishnan V

19-Aug-04 5:37

Which is better from overall performance point of view - Creating a shared memory (~100MB) on the paging file, or on a separate disk file?

Thanks,
Krishnan

Uninstall Blues

Monty²19-Aug-04 3:57

Monty²

19-Aug-04 3:57

There is a key in the registry
UninstallString which contains a Path such as

C:\WINDOWS\system32\UNWISE.EXE C:\WINDOWS\system32\myodbc3_install.LOG
or
rundll32.exe setupapi.dll,InstallHinfSection DefaultUninstall 132 C:\WINDOWS\INF\PCHealth.inf

How do i check that these Paths exists and the uninstall entry in the registry is good.
Parsing it seems to be a real pain

Is there a way by which i can ask windows that or i am stuck with writing a BIG BUGGY parsing algo cause there are tons of different types of entries

any help or suggestion will be welcomed Big Grin | :-D

C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg

http://www.mastishk.com

Re: Uninstall Blues

David Crow19-Aug-04 4:58

David Crow

19-Aug-04 4:58

mailMonty wrote:
How do i check that these Paths exists...

Do you mean with something like _access()? If not, please explain the problem further as I do not understand exactly what the goal is.

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

Re: Uninstall Blues

toxcct19-Aug-04 5:01

toxcct

19-Aug-04 5:01

always so concise in your answers dear David... i appreciate ! Laugh | :laugh:

;)

TOXCCT >>> GEII power

Re: Uninstall Blues

David Crow19-Aug-04 5:07

David Crow

19-Aug-04 5:07

As Steven Covey says:

"Seek first to understand, then to be understood."

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

How to Initialize an array of user selected size

Deepak Samuel19-Aug-04 3:45

Deepak Samuel

19-Aug-04 3:45

Hi,
How do I initilaize an array whose size will be determined by an user input(For example from a edit box ?
I tried this but they didnt work...

numsamples = m_numsamp;
const long arr = numsamples;
ULONG x[arr];
ULONG y[arr];

They returned error 2057 and 2466.
Thanks!

Deepak Samuel.

Re: How to Initialize an array of user selected size

RChin19-Aug-04 3:59

RChin

19-Aug-04 3:59

You need to dynamically allocate your array. This is where pointers comes very handy!

ULONG* arrA = NULL;
int nSize;

<font color=green>// Get size of array from user</font>
..
<font color=green>// allocate array to given size</font>
arrA = new ULONG[nSize];
if(NULL != arrA)
{
   <font color=green>// work with array.</font>
   arrA[0] = 1234;
   cout << _T("yeah baby!") << arrA[0] << endl;

   <font color=green>// don't forget to clean up when finished</font>
   delete [] arrA;
{

I Dream of Absolute Zero

noisy AfxMessageBox

V.19-Aug-04 3:27

19-Aug-04 3:27

Hello,

Does anybody know if you can 'disable' the beep when calling an AfxMessageBox? This is quite annoying.

tnx!!

"If I don't see you in this world, I'll see you in the next one... and don't be late." ~ Jimi Hendrix

Re: noisy AfxMessageBox

RChin19-Aug-04 3:52

RChin

19-Aug-04 3:52

I don't think you can switch it off programmatically from the ::MessageBox() function.

Have a look in your Control Panel, under 'Sounds, Speech, and Audio Devices'. You can control the WAV associated with a windows event, including the message box sound(Default Beep). You can even choose to switch it off from there.

I Dream of Absolute Zero

Program Starts Minized

sweep12319-Aug-04 3:25

sweep123

19-Aug-04 3:25

I have an application which starts another application, but I dont need to see the dialog window of this other program. The user can maximise it if required.

I have tried the following to hide the dialog window in the program:-

this->OnShowWindow (FALSE, 0);   // Place in the InitDlg routine<br />
<br />
and this->ShowWindow (SW_HIDE); // PLaced in the JoyMove routine

but the dialog wind is still visable.

I start the program via CreateProcess (see below):-

::ZeroMemory(&si[0], sizeofsi[0]));  <br />
GetStartupInfo(&si[0]);<br />
si[0].dwX = 0;<br />
si[0].dwY = 0;<br />
si[0].dwFlags = STARTF_USEPOSITION;<br />
CreateProcess(	NULL, <br />
		"c:\\Program Files\\Joystick\\MSCPP.exe",  // Name of app to launch<br />
		NULL,      // Default process security attributes<br />
		NULL,      // Default thread security attributes<br />
		FALSE,     // Don't inherit handles from the parent<br />
		0,		   // Normal priority<br />
		NULL,      // Use the same environment as the parent<br />
		NULL,      // Launch in the current directory<br />
		&si[0],    // Startup Information<br />
		&pi[0]);   // Process information stored upon return CW_USEDEFAULT

Any comments please as I am sure a simple solution exists.

Re: Program Starts Minized

RichardS19-Aug-04 3:51

RichardS

19-Aug-04 3:51

Just change your startup information:

sweep123 wrote:
si[0].dwFlags = STARTF_USEPOSITION;

Try this:

si[0].dwFlags = STARTF_USEPOSITION | STARTF_USESHOWWINDOW;<br />
si[0].wShowWindow = SW_MINIMIZE;

cheers,
Rich

"Programming today is a race between software engineers striving to build bigger and
better idiot-proff programs, and the Universe trying to produce bigger and better idiots.
So far the Universe is winning." -- Rich Cook

Re: Program Starts Minized

sweep12319-Aug-04 5:45

sweep123

19-Aug-04 5:45

Thanks, but no luck.

The program window is NOT minimised.

Re: Program Starts Minized

gamitech19-Aug-04 10:57

gamitech

19-Aug-04 10:57

try ShellExecute
Last parameter set it to SW_HIDE
or ShellExecuteEx
or LoadModule()

gabby

Re: Program Starts Minized

Ryan Binns19-Aug-04 18:25

Ryan Binns

19-Aug-04 18:25

Does the dialog have a minimise button? If it doesn't, you can't minimise it.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Suspending external application

WzR19-Aug-04 3:08

WzR

19-Aug-04 3:08

Hello...
I need to run an external program, suspend at some offset, retrieve register values(like ebx) and continue running external app.

That is the problem Smile | :)

How do run-time patchers work?

P.S.: Please reply to ths@smtp.ru
Thanks...

Using Visual C++ .NET (ClassWizard)

Jon Hulatt19-Aug-04 3:05

Jon Hulatt

19-Aug-04 3:05

Hi Guys,

I'm sure this is a very easy question, but i'm damned if i can find the answer. I've just started using VS.NET instead of VC6- but still for unmanaged, MFC development.

In VC6, I could very simply use classwizard to create an override of CDialog::OnInitDialog, and have VC6 generate a stub function for me (which called the base class implementation).

How do you do this is Visual C++ .NET ? Surely there must be a way.

Thanks

Jon

#include <beer.h>

Re: Using Visual C++ .NET (ClassWizard)

Andrew Walker19-Aug-04 15:19

Andrew Walker

19-Aug-04 15:19

In the class view select the appropriate class that you want to add the handler for. In the properties window, click on the overrides button (little green boxy looking icon). Scroll down to onInitDialog, click in the right hand column, click on the drop down box, select on '<<add>> OnInitDialog', the code should have been added.

You add WM_* event handlers in the same way, except you click on the messages button first.

If you can keep you head when all about you
Are losing theirs and blaming it on you;
If you can dream - and not make dreams your master;
If you can think - and not make thoughts you aim;
Yours is the Earth and everything that's in it.

Rudyard Kipling

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