Re: How to remove this error - C / C++ / MFC Discussion Boards

Re: CPropertySheet::OnInitDialog() exception

bangiev5-May-11 5:20

bangiev

5-May-11 5:20

Hi i assume you fixed the problem . can you give me suggestion

Bringing desktop window to the top without taking focus

casid22-Jun-04 9:47

casid

22-Jun-04 9:47

Off and on for some time I've tried to find the best way to bring a window (whose parent is the desktop) to the top of all the other application windows on some particular event. They could very well be using another application window at the time so I can't allow it to take the focus away as this could result in lost keystrokes. My current implementation of this is basically the following:

HWND hwnd = ::GetForegroundWindow();
::SetWindowPos(myhwnd, hwnd, 0, 0, 0, 0, SWP_NOSIZE|SWP_NOMOVE|SWP_NOACTIVATE);
::SetWindowPos(myhwnd, hwnd, 0, 0, 0, 0, SWP_NOSIZE|SWP_NOMOVE|SWP_NOACTIVATE);

I've investigated numerous other ways over time. This works well but doesn't always work perfectly. Some times focus is stolen and sometimes the z-order isn't correct. These are rare cases and usually involve some specific other application that was in use at the time.

I'm wondering if anyone could offer solutions they've tested and used in the past for performing something similar?

Craig

Re: Bringing desktop window to the top without taking focus

casid22-Jun-04 9:49

casid

22-Jun-04 9:49

Sorry, I meant to code it:

HWND hwnd = ::GetForegroundWindow();
::SetWindowPos(myhwnd, hwnd, 0, 0, 0, 0, SWP_NOSIZE|SWP_NOMOVE|SWP_NOACTIVATE);
::SetWindowPos(hwnd, myhwnd, 0, 0, 0, 0, SWP_NOSIZE|SWP_NOMOVE|SWP_NOACTIVATE);

concatenation

RabiaRabia22-Jun-04 9:24

RabiaRabia

22-Jun-04 9:24

How to concatenate a string and an int

Re: concatenation

ov22-Jun-04 9:30

22-Jun-04 9:30

There are many ways. It depends of type of your string. For null-terminated const char * you can use this one:

char res[128];
const char *str = "Result is: ";
int num = 10;
sprintf(res, "%s%d", str, num);

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Re: concatenation

gamitech22-Jun-04 12:44

gamitech

22-Jun-04 12:44

well a solution would be this one:

int x=466;
char conc[1024];
_itoa(x,conc,10); //converts the int to string now conc="466"
strcat(conc," is a converted number");
//now conc is "466 is a converted number"

Hope this is what you want

gabby

How to remove this error

RabiaRabia22-Jun-04 9:21

RabiaRabia

22-Jun-04 9:21

unresolved external symbol "public: __thiscall CMyProcessesInfo::CMyProcessesInfo(class CWnd *)" (??0CMyProcessesInfo@@QAE@PAVCWnd@@@Z)

Re: How to remove this error

ov22-Jun-04 9:32

22-Jun-04 9:32

try to define this constructor (or include it's .cpp-file in your project)

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Feasability Question: C++ / UDP / MSSQL

brian222222-Jun-04 9:07

brian2222

22-Jun-04 9:07

I have a project and am hoping for input on how I might further consider the feasability of using C++ to implement it. My main problem is that I am only slightly familiar with visual C++.

Project Details:

(1) Embedded device reads data every 4 seconds and transmits a UDP paket to a Server.

(2) C++ application gets packet, pulls out info, and updates MSSQL database.

(3) Web browser loads page and constantly updates the current value for viewing purposes, and other application access the data directly from the database.

So, Step (1) and (3) are no problem. My question involves (2). I will be using visual c++ 6.0.

The only experience I have had with Visual C++ is to take and existing application and make modifications to it basically using examples that were in the code already. I have 3 questions below that are all: "How do I do that?" What I am getting at is what libraries and functions I use to get the functionality, or the correct terminolgy so that I can find some sort of help on each separate topic.

This is an application that must be running continuously, can or should it run as a service? How do I do that? Is it worth the effort that might be involved versus just dropping the exe into the startup folder?

The application must be set up to listen for udp packets on a certain port. How do I do that?

Once I have the packet I will need to yank out the data and do an SQL update. How do I do that? I am familiar with using ADO in ASP pages, is it similar to use in C++?

Any help whatsoever is greatly appreciated. Links to other online material that answer it for me or the names of the libraries and functions that I would use, or anything else that might help is what I think I am looking for.

Thanks for you help!
Brian

Re: Feasability Question: C++ / UDP / MSSQL

palbano22-Jun-04 9:47

palbano

22-Jun-04 9:47

brian2222 wrote:
can or should it run as a service?

Yes

brian2222 wrote:
How do I do that?

http://www.codeproject.com/system/serviceskeleton.asp[^]

brian2222 wrote:
The application must be set up to listen for udp packets on a certain port. How do I do that?

You learn about "Socket" development. It's no small subject and will take some time.

brian2222 wrote:
I am familiar with using ADO in ASP pages, is it similar to use in C++?

The ADO COM interface is of course exactly the same. Working with COM in C++ is going to be very different than in script code or VB. So you have a learning curve there as well. I suggest looking at using the #import statement and the ATL smart pointer templates.

Good luck

"No matter where you go, there your are." - Buckaroo Banzai

-pete

saving modified BMPs

TFB22-Jun-04 8:32

TFB

22-Jun-04 8:32

Anybody out there know a reasonably straight-forward way to save modified CBitmaps??

how to cast cstring into char*?

vividwu22-Jun-04 7:32

vividwu

22-Jun-04 7:32

i need to extract the data to form a Tree ,i must transfer the cstring into char*
i use (lpstr) but compile note not well
so i myself write a function as following:
char* CSelectDlg::change(CString mystr)
{ int len=mystr.GetLength();
char* array=new char(len);
for(int i=0;i

Re: how to cast cstring into char*?

David Crow22-Jun-04 7:35

David Crow

22-Jun-04 7:35

CString str;
const char *cp = (LPCSTR) str;
char *p = (LPSTR) ((LPCSTR) str); // Possible, but use GetBuffer() instead

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

Re: how to cast cstring into char*?

Nitron22-Jun-04 8:04

Nitron

22-Jun-04 8:04

DavidCrow wrote:
CString str;
const char *cp = (LPCSTR) str;
char *p = (LPSTR) ((LPCSTR) str);

WTF | :WTF:

I hope you're kidding. Here:

ms-help://MS.VSCC.2003/MS.MSDNQTR.2003FEB.1033/vclib/html/vclrfCSimpleStringTGetBuffer.htm

~Nitron.

ññòòïðïðB A start

Re: how to cast cstring into char*?

David Crow22-Jun-04 8:25

David Crow

22-Jun-04 8:25

I was not kidding at all. The link you provided is not http. Want to try again?

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

Re: how to cast cstring into char*?

Nitron22-Jun-04 8:48

Nitron

22-Jun-04 8:48

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

~Nitron.

ññòòïðïðB A start

Re: how to cast cstring into char*?

James R. Twine22-Jun-04 8:32

James R. Twine

22-Jun-04 8:32

CString str;<br />
const char *cp = (LPCSTR) str;<br />
char *p = (LPSTR) ((LPCSTR) str);

Truth be told, he answered the Original Poster's question perfectly. The OP did not ask if it was safe or even a good idea to cast a CString into a non-const char*...! (Which, of course, we all know is generally not a good idea at all!)

Peace!

-=- James
Tip for SUV winter driving survival: "Professional Driver on Closed Course" does not mean "your Dumb Ass on a Public Road"!
Articles -- Products: Delete FXP Files & Check Favorites

Re: how to cast cstring into char*?

vividwu22-Jun-04 8:13

vividwu

22-Jun-04 8:13

hi:your advice is ok by tring ,but can you explain why my method has some bug?
in addition i seldom have conscious to use LPCSTR LPSTR LPSTR , Please you give me a simple introduction about when to use them ?
thx again

Re: how to cast cstring into char*?

David Crow22-Jun-04 8:22

David Crow

22-Jun-04 8:22

There are only two ways of getting at the internal CString buffer. One is to use the LPCSTR operator and the other is to use the GetBuffer() method. One is read-only while the other is writeable. Since you did not indicate a need to update the buffer, I provided you with the LPCSTR way.

vividtang wrote:
i seldom have conscious to use LPCSTR LPSTR LPSTR

I do not understand this. Do you mean you seldom have a need to use them?

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

Re: how to cast cstring into char*?

mtzlplyk22-Jun-04 10:47

mtzlplyk

22-Jun-04 10:47

vividtang wrote:
in addition i seldom have conscious to use LPCSTR LPSTR LPSTR , Please you give me a simple introduction about when to use them ?

Use them all the time ! MFC does Smile | :)

Re: how to cast cstring into char*?

vcplusplus22-Jun-04 7:44

vcplusplus

22-Jun-04 7:44

int len=mystr.GetLength() + 1; // Add one for NULL
char* array=new char(len);
lstrcpy(array, mystr);

// MSDN example for CString::GetBuffer
CString s( "abcd" );
LPTSTR p = s.GetBuffer( 10 );
strcpy( p, "Hello" );   // directly access CString buffer
s.ReleaseBuffer( );

Re: how to cast cstring into char*?

James R. Twine22-Jun-04 8:26

James R. Twine

22-Jun-04 8:26

      // MSDN example for CString::GetBuffer<br />
      CString s( "abcd" );<br />
      LPTSTR p = s.GetBuffer( 10 );<br />
      strcpy( p, "Hello" );   // directly access CString buffers.<br />
      ReleaseBuffer( );

Yes, yet another bad example from MSDN! No enforcement of the buffer size obtained (should have used strncpy(...)), and no exception handling for example.

IOW, typical high-quality MSDN documentation/examples that newer developers can learn all kinds of bad habits from! Smile | :)

Peace!

-=- James
Tip for SUV winter driving survival: "Professional Driver on Closed Course" does not mean "your Dumb Ass on a Public Road"!
Articles -- Products: Delete FXP Files & Check Favorites

Re: how to cast cstring into char*?

palbano22-Jun-04 8:39

palbano

22-Jun-04 8:39

James R. Twine wrote:
Yes, yet another bad example from MSDN!

A problem that they have acknoledged in MSDN Magazine Editors Note i believe. The site is huge with years of information built up. They are addressing the issue. Until then you can find newer resources there if you try.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsecure/html/strsafe.asp[^]

James R. Twine wrote:
typical high-quality MSDN documentation/examples that newer developers can learn all kinds of bad habits from!

Please point us to the more complete more correct online resource that we should be using instead of MSDN Roll eyes | :rolleyes:

"No matter where you go, there your are." - Buckaroo Banzai

-pete

Re: how to cast cstring into char*?

Nitron22-Jun-04 8:50

Nitron

22-Jun-04 8:50

palbano wrote:
Please point us to the more complete more correct online resource that we should be using instead of MSDN

I thought that's what CP is for Poke tongue | ;-P

~Nitron.

ññòòïðïðB A start

Re: how to cast cstring into char*?

James R. Twine22-Jun-04 11:00

James R. Twine

22-Jun-04 11:00

The strsafe functions are somewhat new, coming out right after the "secure code initiative" (or whatever it was) stuff that MS was touting a few years back after the release of .Net. That is a loooong time from when much of the bad examples out there were written, so if "they are addressing the issue", it sure took a long time... Besides, that is but one of many kinds of bad examples.

palbano wrote:
Please point us to the more complete more correct online resource that we should be using instead of MSDN

No problem: Common Sense.[^] What is more "online" than your own brain? (And did you really need a pointer to that? Suspicious | :suss:

)

-=- James
Tip for SUV winter driving survival: "Professional Driver on Closed Course" does not mean "your Dumb Ass on a Public Road"!
Articles -- Products: Delete FXP Files & Check Favorites

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