C / C++ / MFC

Re: what path format does CFileDialog return? C:\ or C:\\?

14-Aug-02 3:35

single \

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

ns14-Aug-02 3:59

14-Aug-02 3:59

I wanted commas to replace the backslashes, so I tried

CString m_szlstfile = fileDlg.GetPathName();

m_szlstfile.Replace('\\', ',');

AfxMessageBox(m_szlstfile);

which worked, whereas if I did

Replace('\', ',');<br />

it complained that there was a newline in the sequence. So apparentlt there is a \\ somewhere in the process ?? Confused | :confused:

Re: what path format does CFileDialog return? C:\ or C:\\?

Nish Nishant14-Aug-02 4:05

Re: what path format does CFileDialog return? C:\ or C:\\?

14-Aug-02 4:05

No, it's a \ alright. But when you pass a string to Replace(...) you have to use \\ because \\ is the escape sequence for \ Smile | :)

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

C^hris L^osinger14-Aug-02 4:08

C^hris L^osinger

14-Aug-02 4:08

no, there is no \\ the sequence. the first \ escapes the second ' , changing it from a special C/C++ metacharacter to a literal string character. so, your statement ends up meaning roughly the same as this:

Replace('x, ',');

and that can't be parsed

bottom line: if you want a \ in a string, you have to use \\.

-c

Conservative:
One who admires radicals centuries after they're dead.
-- Leo C. Rosten

image effects!

Exception Handling

BlackRider14-Aug-02 3:27

BlackRider

14-Aug-02 3:27

I'm TRYING to catch database exception and output that to an error file. Here's the CATCH code :

catch (CdbException)
{
FILE* errorfile;
errorfile=fopen("c:\\cristi\\error.err","a");
fprintf(errorfile,"v,dmlkvmdsv");
for (long ct = 0; ct < dben.Errors.GetCount(); ct++)
{
fprintf(errorfile,_T("\t Error #%ld: #%ld -- %s\n"),
ct,
DBERR(dben.Errors[ct].GetNumber()),
dben.Errors[ct].GetDescription());
}
fclose(errorfile);
return;
}

This code just won't work. I get nothing in the file. Nothing. It's not even accessed.

This other code below that prints the error data to the screen works.

catch (CdbException)
{
for (long ct = 0; ct < dben.Errors.GetCount(); ct++)
{
printf(_T("\t Error #%ld: #%ld -- %s\n"),
ct,
DBERR(dben.Errors[ct].GetNumber()),
dben.Errors[ct].GetDescription());
}
return;
}

Now. ---> In both cases I get this error message:
Debug Assertion Failed!
Program: ...program
File:dbgheap.c
Line:1044
Expression: _CrtIsValidHeapPointer(pUserData)

I belive the second code works because of the printf lack of buffering so that the error message that I display at the console displays faster than the debug assertion failed error. Anyway, this isn't the problem. The problem is why do I get that error message. What happend over there. Anyone encountered this problem before ?

Thank you!

Re: Exception Handling

Niklas L14-Aug-02 4:57

Niklas L

14-Aug-02 4:57

Are you sure dben.Errors[ct].GetDescription() is returning a char* and not some other kind of string like CString or wchar_t*? That's the only thing I can see by just looking at your code.

CreateProcess

Dave_14-Aug-02 3:20

14-Aug-02 3:20

I have been trying to execute a console application (32 bit), and get it's output from a Win32 (MFC) application. I have tried the CSpawn article on www.codeproject.com, but it does not work fur Windows98, and does not wait until the program exits they way I need it to.

I have also tried the MSDN articles. They mention that 16-bit console apps need an extra CreateProcess, but I don't think I need that since the console app is a 32-bit app? I do not ever create console apps, so am I wrong about this? Are all console apps considered 16-bit?

I'd rather not re-invent something if someone has already solved this one.

Any ideas on where to look?

Thanks,

Dave

Tomasz Sowinski14-Aug-02 4:51

Tomasz Sowinski

14-Aug-02 4:51

Check KB article Q190351 "HOWTO: Spawn Console Processes with Redirected Standard Handles".

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

Never argue with an idiot, he'll bring you to his level and beat you with experience.

Dave_14-Aug-02 4:56

14-Aug-02 4:56

Thanks, I have tried this, and had problems. Have you ever tried to implement code from this article?

Tomasz Sowinski14-Aug-02 4:59

Tomasz Sowinski

14-Aug-02 4:59

No. What is the problem?

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

Never argue with an idiot, he'll bring you to his level and beat you with experience.

Dave_14-Aug-02 5:02

14-Aug-02 5:02

Thanks anyway, there are several problems, but it's not worth getting into. I was hoping to find someone that had actually implemented something similar to what I am attempting.

Andreas Saurwein14-Aug-02 6:00

Andreas Saurwein

14-Aug-02 6:00

It just doesnt work Frown | :(

Thats why I wrote the CSpawn class.

int x=1, y=5; 
x^=y^=x^=y; // whats the content of x and y now?
<a href="http://www.codeproject.com/useritems/StupidXORTrick.asp" target="_blank">ClickHereForHelp();</a>

Andreas Saurwein14-Aug-02 6:03

Andreas Saurwein

14-Aug-02 6:03

Whats wrong with CSpawn? What does it do under Win98? As far as I know it should work. Maybe I can give you a hint on how to adapt it (well, I wrote it).

int x=1, y=5; 
x^=y^=x^=y; // whats the content of x and y now?
<a href="http://www.codeproject.com/useritems/StupidXORTrick.asp" target="_blank">ClickHereForHelp();</a>

Dave_14-Aug-02 6:25

14-Aug-02 6:25

Thanks,

I think it probably does very well when using it the way you intended.

I am using it as a "read only", and wait until completed type of operation.

I was able to get it going under w98 by ignoring the following failure:

(In Execute(...))

if (!SetStdHandle(STD_OUTPUT_HANDLE, m_hSaveStdout)){
}

For some reason, this fails under W98, but not NT. It does not seem to affect anything, so I am ignoring the failure for now.

Any idea what is happening?

Thanks,

Dave

Andreas Saurwein14-Aug-02 15:02

Andreas Saurwein

14-Aug-02 15:02

You can modify the behavior as you need it when you look at the comment to CSpawn.

About the failure under W98 I have no clue as I have no W98 system available (its almost obsolete anyway). Maybe someone with W98 experience might tell.

int x=1, y=5; 
x^=y^=x^=y; // whats the content of x and y now?
<a href="http://www.codeproject.com/useritems/StupidXORTrick.asp" target="_blank">ClickHereForHelp();</a>

Dave_15-Aug-02 1:57

15-Aug-02 1:57

Thanks for the reply. I was able to make some modifications to make it work the way I needed it. I'm going to try to see why the one failure happens in W98. What you have written is great stuff. I'm sure I would have had no problems if I were using it the way you intended.

Stuart Dootson14-Aug-02 21:03

Stuart Dootson

14-Aug-02 21:03

Hows this - note that there may be some missing headers - I've just cut'n'pasted this out of a working application, so it's missing context...

#include <windows.h>
#include <malloc.h>
#include <string>
namespace std {
#ifdef _UNICODE
  typedef wstring tstring;
#else
  typedef string tstring;
#endif
};
std::tstring RunProcessAndCaptureOutput(LPCTSTR CmdLine, DWORD maxWaitTime = INFINITE)
{
  LPTSTR copyOfCmdLine = LPTSTR(alloca(sizeof(TCHAR) * (lstrlen(CmdLine) + 1)));
  lstrcpy(copyOfCmdLine, CmdLine);
  std::tstring s;
  SECURITY_ATTRIBUTES SecAttr;
  SecAttr.nLength = sizeof(SecAttr);
  SecAttr.lpSecurityDescriptor = NULL;
  SecAttr.bInheritHandle = TRUE;

  HANDLE hRead, hWrite;
  if (::CreatePipe(&hRead, &hWrite, &SecAttr, 0)) {
    STARTUPINFO StartupInfo;
    ZeroMemory(&StartupInfo, sizeof(StartupInfo));
    StartupInfo.cb = sizeof(StartupInfo);
    StartupInfo.dwFlags = STARTF_FORCEOFFFEEDBACK|STARTF_USESTDHANDLES;
    StartupInfo.hStdError = hWrite;
    StartupInfo.hStdOutput = hWrite;
    PROCESS_INFORMATION ProcessInfo;

    if (::CreateProcess(NULL, copyOfCmdLine, NULL, NULL, TRUE, DETACHED_PROCESS, NULL, NULL, &StartupInfo, &ProcessInfo)) {
      std::tstring capturedOutput;
      const DWORD smallWaitTime = 100;
      __int64 ftEnd;
      GetSystemTimeAsFileTime(LPFILETIME(&ftEnd));
      ftEnd += __int64(maxWaitTime) * __int64(10000);
      CloseHandle(hWrite);
      while (::WaitForSingleObject(ProcessInfo.hProcess, smallWaitTime) != WAIT_OBJECT_0) {
        EmptyPipeAndAppendToString(hRead, capturedOutput);
        __int64 ftNow;
        GetSystemTimeAsFileTime(LPFILETIME(&ftNow));
        if (ftNow > ftEnd) {
          s += "Command \"";
          s += CmdLine;
          s += "\" timed out.";
          s += " Partial output received\r\n\r\n";
          break;
        }
      }
      EmptyPipeAndAppendToString(hRead, capturedOutput);
      CloseHandle(ProcessInfo.hProcess);
      CloseHandle(ProcessInfo.hThread);
      s += capturedOutput;
      s += "\r\n\r\n";
    }
    else {
      CloseHandle(hWrite);
      s += "Error creating process with command \"";
      s += CmdLine;
      s += "\"\r\n\r\n";
    }
    CloseHandle(hRead);
  }
  else {
    s += "Error creating pipe\r\n\r\n";
  }
  return s;
}

Stuart Dootson

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

Dave_15-Aug-02 1:55

15-Aug-02 1:55

Thank you very much, I'll give it a try.

CFont query

Nish Nishant14-Aug-02 2:34

14-Aug-02 2:34

Assume I have a CFont object in my CWnd derived class. And assume I wanna repeatedly change the font of my CWnd derived class. Say I do this :-

CFont *pf = GetFont();
LOGFONT lf;
pf->GetLogFont(&lf);	
//...
//modify lf here
//...
m_font.Detach();
m_font.DeleteObject();
m_font.CreateFontIndirect(&lf);
SetFont(&m_font);

Am I doing it right? Or is there a leak?

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

Re: CFont query

Shog⁹14-Aug-02 3:43

Shog⁹

14-Aug-02 3:43

Get rid of the Detach() call, or DeleteObject() won't actually do anything. Otherwise it looks good to me.

---

Shog⁹
If I could sleep forever, I could forget about everything...

Re: CFont query

Roger Allen14-Aug-02 3:43

Roger Allen

14-Aug-02 3:43

There is a leak,

m_Font.Detach() clears the HFONT handle from the m_Font wrapper class object so your not deleting anything when calling m_Font.DeleteObject().
Just remove the m_Font.Detach() line.

Roger Allen
Sonork 100.10016

I think I need a new quote, I am on the prowl, so look out for a soft cute furry looking animal, which is really a Hippo in disguise. Its probably me.

Thanks guys

Nish Nishant14-Aug-02 3:51