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First you would need to find out if the database is actually thread safe. Unless there is a compelling reason to use multiple threads I suggest you don't: writing multithreaded applications is hard. Debugging buggy multithreaded applications can be a nightmare.
Steve
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Hihi,
I'm trying to use CreateFile to check whether or not a certain device is connected to the serial port. Here's the code:
HANDLE testport = CreateFile("\\\\.\\COM1",
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
0,
NULL );
It's failing, and GetLastError is returning 87, ERROR_INVALID_PARAMETER.
This portion of the code is for WinCE, for WinXP I use "COM1:" instead of "\\\\.\\COM1"
Anyone know what could be wrong?
The device is connected to the COM port, so the result should not be a failure.
Kelly Ryan
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The Windows CE documentation for CreateFile in MSDN says that for a com port, you must include the colon after the name, and makes no mention of the need for the \\.\ beforehand. I'm no CE expert, but why are you using different filenames for CE and XP?
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The code is pulled from another project we have here which deals with both WinCE and XP and those are the names it uses. I started out with both the same and after I was having problems, took a look at that code and decided to try it instead since it seems to work in the other project. Unfortunately it doesn't work either.
Kelly Ryan
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With a bunch more messing around, now it produces error 2, ERROR_FILE_NOT_FOUND instead of error 87. Does anyone have any ideas??
Kelly Ryan
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Finally got it; I had to print the com port name into a TCHAR before I passed it to CreateFile. Bleeh...
Kelly Ryan
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Hi experts,
How can I read the file header to determine the type of the file?
Let say, the pdf ile will have %pdf in the header. So after reading the header, I can decide which application to use to open that file.
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To do this effectively would be hard. The FindMimeFromData API may be of interest to you however.
Steve
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i know it would be hard.
but i already have the list to of file extension and its magic code to identified which type of file.
just need to know how to read the file header. I remember I did read file header in college. but i just dont' really sure if I had used reading file in binary fomrat for header.. couldnt' do it anymore. If any of you know how to read the file header, please help me out.
Thanks
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CreateFile with OPEN_EXISTING followed by a ReadFile of a certian number of bytes would do the trick.
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Hi,
I have a dialog with a colored background (no bitmap) with the controls being transparent. Now I can get the edit boxes to redraw correctly, BUT I cannot get the sliders to redraw correctly.
I have seen custom CSliderCtrl classes that may do this but I am hoping that I can fix the problem with just a small amount of code.
Thanks in advance for any help!
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Jerry Ott III wrote: I have a dialog with a colored background (no bitmap)
Where are you doing the coloring?
Jesus Loves ![Rose | [Rose]](https://codeproject.freetls.fastly.net/script/Forums/Images/rose.gif)
--Owner Drawn
--Nothing special
--Defeat is temporary but surrender is permanent
--Never say quits
--Jesus is Lord
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Below is what I have for the OnCtrlColor and the OnEraseBkgnd functions that are in the class with the slider.
I'm still very new to the MFC stuff so basically just found parts of code other people have shown and have used that with hopes of actually learning it so I can make my own things.
Right now I just have the sliders not being transparent or anything so that they redraw correctly.
HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
HBRUSH hbr;
pDC->SetBkMode(TRANSPARENT);
pDC->SetTextColor(RGB(255,255,255));
hbr = (HBRUSH)GetStockObject( NULL_BRUSH );
return hbr;
}
BOOL OnEraseBkgnd(CDC* pDC)
{
CPen myPen[64] ;
int i ;
CRect rect ;
for (i = 0 ; i <= 60 ; i++)
myPen[i].CreatePen(PS_SOLID, 1, RGB (0,0,(i * 4)));
CPen *oldPen = pDC->SelectObject(&myPen[0]) ;
GetClientRect(&rect);
for(i = 0 ; i <= rect.bottom;)
{
pDC->MoveTo(0, i);
pDC->LineTo(rect.right, i);
i++;
pDC->SelectObject (&myPen[i * 64 / rect.bottom]);
}
pDC->SelectObject(oldPen) ;
return TRUE ;
}
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Hi, God Morning/afternoon,
May I know how to work with c files on a visual C++ 6.0 IDE?
Some people say it is easy, howver I am encountering a lot of problems.
examples simple. project.
the c file looks like:
/* ------------- */
/* mon_include.c */
/* ------------- */
#include <stdio.h>
main()
{
#include "mon_include.h"
i = 10 ;
j = 20 ;
k = i+j ;
printf("k = %d\n",k);
}
and the *.h file
/* ------------- */
/* mon_include.h */
/* ------------- */
int i,j ;
int k ;
/* ------------- */
Thanks a lot,
I work on Visual C++ 6.0 introductory edition.
T.
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I think this is what you want to do?
{
FILE *flog;
i = 10 ;
j = 20 ;
k = i+j ;
flog = fopen("c:\\directory\\test.txt", "w");
fprintf( flog,"%s, %d\n","k=",k );
fclose ( flog );
}
If you look in the directory called "directory" you should find your file (test.txt).
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 I think this is what you want to do?
Tombo
Would you please tell how that guy can use this, please check before you post something .
Regards,
FarPointer
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thierrypp wrote: ...howver I am encountering a lot of problems.
And what would those problems be?
thierrypp wrote: #include "mon_include.h"
Did you mean to have this statement inside of main()?
"The words of God are not like the oak leaf which dies and falls to the earth, but like the pine tree which stays green forever." - Native American Proverb
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thank you, but really, more generally, can a common C programme be compiled on a Visual C++ 6.0 compiler?
and how?
Regards,
T.
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thierrypp wrote: can a common C programme be compiled on a Visual C++ 6.0 compiler?
Certainly. Why wouldn't it?
"The words of God are not like the oak leaf which dies and falls to the earth, but like the pine tree which stays green forever." - Native American Proverb
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I have a set of C files which can be compiled on a C-compiler, but not at all on Visual C++6.0.
Maybe you could tell me the right procedure to do it.........
Or I can send you examples?
Thank you,
T.
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for example:
/* ---------- */
/* premier2.c */
/* ---------- */
#include <stdio.h>
#include <math.h>
main()
{
int nb, diviseur1, diviseur2,reste ;
int trouve,i ,racinecar,limite ;
int nb_iterations=1;
printf("Entrez un Nombre :");
scanf("%d",&nb);
/* partie entiere de la racine carre+1 */
limite=sqrt(nb)+1;
trouve=0 ;
if (nb != 2) /* 2 est premier */
{
/* on retire le cas des nombres pairs */
reste=nb%2 ;
if (reste == 0)
{
trouve=1 ;
/* on memorise les diviseurs */
diviseur1=2 ;
diviseur2=nb/2 ;
}
else
{
/* teste tous les diviseurs impairs */
i=3;
while ( (! trouve) && (i<=limite) )
{
nb_iterations++;
reste= nb%i ;
if (reste == 0)
{
trouve=1 ;
/* on memorise les diviseurs */
diviseur1=i ;
diviseur2=nb/i ;
}
i+=2 ;
}
}
}
if (trouve)
{
printf("%d n'est pas premier !\n",nb);
printf("il est divisible par %d et %d\n",diviseur1,diviseur2);
}
else
{
printf("%d est un nombre PREMIER !\n",nb);
}
printf("RŽsultat obtenu en %d itŽrations\n",nb_iterations);
}
result:
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/premier2.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.
premier2.exe - 2 error(s), 0 warning(s)
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What type of project is this .c file a part of? What preprocessor definitions do you have defined? You need _WIN32 and _CONSOLE at a minimum. Also be sure /subsystem:console is one of the linker options.
"The words of God are not like the oak leaf which dies and falls to the earth, but like the pine tree which stays green forever." - Native American Proverb
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honestly here I am a bit lost....
well ...here is an example of a typical c file, complete!
I have VC++ 6.0 standard edition.
But I am really a newbie in converting c files on VC++ 6.0
Maybe you could tell me how to proceed and which changes?
Usually, I click on the file and immediatelly the VC++ appears..
Thanks,
T
-------->example of a comple c file
/* ------------------ */
/* liste_structure2.c */
/* ------------------ */
#include <stdio.h>
#include <stdlib.h>
#define TAILLE_NOM 20
#define TAILLE_PRENOM 30
/* --- sous-programmes --- */
void saisie() ;
void affichage() ;
struct etudiant *recherche(char nom_recherche[]);
void modification() ;
/* --- variables globales --- */
struct etudiant {
struct etudiant *pred ;
char nom[TAILLE_NOM] ;
char prenom[TAILLE_PRENOM];
int age ;
struct etudiant *succ ;
} ;
struct etudiant *debut_liste,*fin_liste;
int nbeleves=0;
/* ===== PROGRAMME ===== */
main()
{
char choix=' ', ch_saisie[20];
debut_liste = NULL;
fin_liste = NULL;
while (choix!='q')
{
printf("-1- Saisie d'une liste\n");
printf("-2- Affichage\n");
printf("-3- Modification d'un Žlve\n");
printf("-q- quitter\n");
printf("Choix : ");
scanf("%s",ch_saisie);
choix=ch_saisie[0];
switch(choix)
{
case '1' : saisie();
break;
case '2' : affichage();
break;
case '3' : modification();
break;
case 'q' : printf("Au revoir\n");
break;
default : printf("Choix non valide\n");
break;
}
}
}
/* === chargement de la liste === */
void saisie()
{
struct etudiant *nouv_eleve,*eleve_actuel;
int termine = 0 ;
/* --- boucle de saisie --- */
while (! termine)
{
nouv_eleve = malloc(sizeof(struct etudiant));
printf("Entrez un nom ( nom=fin pour terminer):");
scanf("%s",nouv_eleve->nom);
termine=((strcmp(nouv_eleve->nom,"fin"))==0) ;
if (! termine) /* saisie du reste */
{
printf("Entrez un prŽnom:") ;
scanf("%s",nouv_eleve->prenom);
printf("Entrez un ‰ge:") ;
scanf("%d",&(nouv_eleve->age));
nouv_eleve->pred=NULL ;
nouv_eleve->succ=NULL ;
if (debut_liste == NULL)
{ /* Liste vide. C'est le seul element */
debut_liste = nouv_eleve ;
fin_liste = nouv_eleve ;
}
else
{ /* ajout en fin de liste */
fin_liste->succ = nouv_eleve ;
nouv_eleve->pred = fin_liste ;
fin_liste = nouv_eleve ;
}
/* on compte le nombre d'eleves */
nbeleves++ ;
}
}
}
/* === affichage === */
void affichage()
{
struct etudiant *eleve_actuel;
/* --- boucle d'affichage --- */
printf("--- %d Žlves ---\n",nbeleves);
eleve_actuel=debut_liste ;
while (eleve_actuel != NULL )
{
printf("%-10s",eleve_actuel->nom) ;
printf("%-10s",eleve_actuel->prenom);
printf("%3d\n",eleve_actuel->age) ;
eleve_actuel = eleve_actuel->succ ;
}
}
/* === recherche sur critere === */
struct etudiant *recherche(char nom_recherche[])
{
int trouve=0;
struct etudiant *eleve_actuel;
/* --- boucle de recherche --- */
eleve_actuel=debut_liste ;
while ((!trouve) && (eleve_actuel != NULL))
{
trouve=(strcmp(eleve_actuel->nom,nom_recherche)==0);
if (!trouve)
eleve_actuel = eleve_actuel->succ ;
}
if (!trouve)
eleve_actuel = NULL ;
return eleve_actuel ;
}
/* === modification === */
void modification()
{
char nom_modif[TAILLE_NOM];
struct etudiant *eleve_modif;
/* saisie du nom a modifier */
printf("Nom de l'Žlve:");
scanf("%s",nom_modif);
/* recherche */
eleve_modif=recherche(nom_modif);
if (eleve_modif!=NULL)
{
/* affichage */
printf("%-10s",eleve_modif->nom) ;
printf("%-10s",eleve_modif->prenom);
printf("%3d\n",eleve_modif->age) ;
/* modifications */
printf("Nouveau Nom : ");
scanf("%s",eleve_modif->nom);
printf("Nouveau Prenom : ");
scanf("%s",eleve_modif->prenom);
printf("Nouvel Age : ");
scanf("%d",&(eleve_modif->age));
}
else
printf("%s non trouvŽ\n",nom_modif);
}
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There's no need to post all of this code. Most, if not all, of it is irrelevant. Open Visual Studio. Select New from the File menu. Click the Projects tab. Near the bottom of the list, select Win32 Console Application, give the project a name, and click the OK button. On the Step 1 of 1 dialog box, select one of the four radio buttons (e.g., A "Hello World" application). Click the Finish button. Click the OK button. Now open the main .cpp file and paste your code into it, overriding whatever is there. Press F7 to compile and link. Does that help?
"The words of God are not like the oak leaf which dies and falls to the earth, but like the pine tree which stays green forever." - Native American Proverb
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yes,
but there an error message:
Compiling...
ooooo.cpp
c:\documents and settings\atvd\desktop\new folder00ppp\ooooo\ooooo.cpp(161) : fatal error C1010: unexpected end of file while looking for precompiled header directive
Error executing cl.exe.
ooooo.exe - 1 error(s), 0 warning(s)
and when clicking on the error message , it shows the end, after the last }
maybe I should ad a main...? how...?
Thanks a lot!
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