Re: Relational Database - C / C++ / MFC Discussion Boards

kil ramesh14-Feb-06 20:08

14-Feb-06 20:08

I want to perform some action whenever folder selection occured.So, I want to catch the Shell View(List View) events.Plz send any material or code regarding this topic.

How to stop mouse hover notification

BicycleTheif14-Feb-06 19:55

BicycleTheif

14-Feb-06 19:55

Hi,

In my application i have two views say View1 and View2. When the data in the document changes each view is notified synchronously. But if i hover mouse over the view2 when the the data in document is changing and the notification is not yet sent a event is fired by mouse hover even though i have used CWaitCursor in document. I need to prevent this as its trying to access the old data when new data is loading.

Any help please..

Thanks in advance..

Nithya..

Network connection status checking

Tony Kurishunkal14-Feb-06 19:42

Tony Kurishunkal

14-Feb-06 19:42

Any one help me to solve this problem I used ISNetworkAlive to check my lan network connection status but it is not working. Also I used NetServerEnum it is also not working in some systems . Any one please sugest me an alternative method. any status chane message is there.

Re: Network connection status checking

David Crow15-Feb-06 4:09

David Crow

15-Feb-06 4:09

Aby Skaria wrote:
Any one please sugest me an alternative method.

See here.

"The greatest good you can do for another is not just to share your riches but to reveal to him his own." - Benjamin Disraeli

Re: Network connection status checking

ThatsAlok16-Feb-06 2:33

ThatsAlok

16-Feb-06 2:33

Aby Skaria wrote:
ny one please sugest me an alternative method. any status chane message is there.

http://support.microsoft.com/?id=321381[^]

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Client Edge of Progress Bar?

Owner drawn14-Feb-06 19:38

Owner drawn

14-Feb-06 19:38

I have removed all extended styles and WS_BORDER style to get rid of the raised border around the progress.

But this doesn't seem to work. Can somebody help?

Owner drawn
Jesus Loves

Relational Database

moodsey21114-Feb-06 19:27

moodsey211

14-Feb-06 19:27

hello... I'm kinda new in using visual C++ in a relational database. I would just like to ask help if someone has a sample code for connecting updating and closing a database. An ADODC or a DAO will work fine with me. Thanks...

--------------------------------Life is simple, You just complicate things----------------------------

-- modified at 1:44 Wednesday 15th February, 2006

Re: Relational Database

Ashutosh_shashi14-Feb-06 19:33

Ashutosh_shashi

14-Feb-06 19:33

tell the adjectly how u want to connect..
Through ODBC , DAO or .. any other way..
Then i will send u a sample code for that

Ashutosh

Re: Relational Database

moodsey21114-Feb-06 19:43

moodsey211

14-Feb-06 19:43

I'm using ADODC. But you could send me an example for a DAO. I'm choosing from the two. And i'm a little bit confuse...

-----------------------------------Life is simple, You just Complicate Things-----------------------------

Re: Relational Database

Ashutosh_shashi14-Feb-06 22:11

Ashutosh_shashi

14-Feb-06 22:11

Sample Code for DAO-----> Try this--->

CString csQuery; -->à SQL Query
CsaoDatabase pUserDB = new CDaoDatabase();

//Open DataBase in Read Only Mode
m_pUserDB->Open(Path_of_Database,FALSE, TRUE, _T(""));

CDaoRecordset m_pDaoUserRS = new CDaoRecordset(m_pUserDB);
m_pDaoUserRS->Open(AFX_DAO_USE_DEFAULT_TYPE,csQuery,dbReadOnly);

COleVariant varValue;
m_pDaoUserRS->GetFieldValue("Field_Name_of_Database",varValue);

Ashutosh

Re: Relational Database

David Crow15-Feb-06 4:12

David Crow

15-Feb-06 4:12

moodsey211 wrote:
An ADODC...

Isn't that a VB thing?

Anyway, see here.

"The greatest good you can do for another is not just to share your riches but to reveal to him his own." - Benjamin Disraeli

memory leak!!!!!!

naguu14-Feb-06 18:39

naguu

14-Feb-06 18:39

In my code i have a situation like..

char * getmestring()
{
char *str = new char[20];
str = "myname";
return str; --> str not at all release..
}
int main()
{
char name = getmestring();
cout<<name<<endl;
if(name="" !="NULL)"
="" {
="" delete="" []="" name;="" --=""> this is causing the debug assertion failed..
}
}
can u give me some idea to remove leaks in that piece of code..

nagesh

-- modified at 0:40 Wednesday 15th February, 2006

Re: memory leak!!!!!!

namaskaaram14-Feb-06 18:42

namaskaaram

14-Feb-06 18:42

char *name = getmestring();

cheerz!

dont want,dont want thinking,climbing on head and jumping grass!
(venda venda ennu vicharikumbol thellayill keyaree chadunnoda pulle!)

Re: memory leak!!!!!!

Stephen Hewitt14-Feb-06 18:55

Stephen Hewitt

14-Feb-06 18:55

naguu wrote:
char * getmestring()
{
char *str = new char[20];
str = "myname";
return str; --> str not at all release..
}

The memory you allocate with the new statement isn't being used at all. The "str = "myname";" line doesn't copy the string; it copies over the address of the memory you allocated with new with the address of the string literal "myname".

This is probably what you mean:

char * getmestring()
{
  char *str = new char[20];
  strcpy(str, "myname");
  return str; --> str not at all release..
}

Steve

Re: memory leak!!!!!!

Ashutosh_shashi14-Feb-06 19:20

Ashutosh_shashi

14-Feb-06 19:20

Try this ................
int main()
{
char *name = getmestring(); --> modify this line
cout<<name<<endl;
if(name !="NULL)
{
" name="NULL;" ---=""> Add this line
delete [] name; --> this is causing the debug assertion failed..
}
}

Inform me if success...

Ashutosh

Re: memory leak!!!!!!

namaskaaram14-Feb-06 19:42

namaskaaram

14-Feb-06 19:42

int main()
{
char *name = getmestring(); --> modify this line
cout<<name<<endl;
if(name != NULL)
{
name = NULL; ---> Add this line
delete [] name; --> this is causing the debug assertion failed..
}
}

~~assigning name =NULL and then deleting it will give u an error since u r trying to delete a block that points to the null address!!!!~~rather the code should be more like.....

int main()
{
char *name = NULL;  
name = getmestring(); 
cout<<name<<endl;

if(name != NULL)
delete [] name;

}

cheerz!

dont want,dont want thinking,climbing on head and jumping grass!
(venda venda ennu vicharikumbol thellayill keyaree chadunnoda pulle!)

-- modified at 3:35 Wednesday 15th February, 2006

Re: memory leak!!!!!!

Ryan Binns14-Feb-06 19:51

Ryan Binns

14-Feb-06 19:51

namaskaaram wrote:
assigning name =NULL and then deleting it will give u an error since u r trying to delete a block that points to the null address!!!!

No it won't. It won't do as intending, but deleteing a NULL pointer is a perfectly valid operation - it does not cause errors.

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"

Re: memory leak!!!!!!

BadKarma14-Feb-06 20:29

BadKarma

14-Feb-06 20:29

But then again there will be a memory leak

codito ergo sum

Re: memory leak!!!!!!

Ryan Binns14-Feb-06 21:27

Ryan Binns

14-Feb-06 21:27

Usually, but that's not the point I was making. His statement was that deleteing a NULL pointer causes an error because the pointer is NULL. This is not correct.

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"

Re: memory leak!!!!!!

BadKarma14-Feb-06 21:43

BadKarma

14-Feb-06 21:43

I know,

I was just trying to point out for naguu that altough setting a pointer to NULL and then deleting wont cause an error it will cause a memory leak. Which was (one of) his first problems.

To conclude:

char * getmestring()
{
char *str = new char[20];

// FROM <a href = "http://www.codeproject.com/script/comments/forums.asp?msg=1371347&forumid=1647#xx1371359xx" rel="nofollow">Stephen Hewitt</a>[<a href = "http://www.codeproject.com/script/comments/forums.asp?msg=1371347&forumid=1647#xx1371359xx" target = "_blank" rel="nofollow">^</a>]
// str = "myname";
strcpy(str, "myname"); 
return str;
}
int main()
{

// FROM <a href = "http://www.codeproject.com/script/comments/forums.asp?msg=1371347&forumid=1647#xx1371347xx" rel="nofollow">namaskaaram</a>[<a href = "http://www.codeproject.com/script/comments/forums.asp?msg=1371347&forumid=1647#xx1371347xx" target = "_blank" rel="nofollow">^</a>]
//char name = getmestring();
char *name = getmestring(); 
cout<<name<<endl;
if(name != NULL)
{
delete [] name; 
}
}

codito ergo sum

Re: memory leak!!!!!!

Ryan Binns14-Feb-06 21:48

Ryan Binns

14-Feb-06 21:48

Fair enough Smile | :)

BadKarma wrote:
//char name = getmestring();char *name = getmestring();

I assumed here he just typed into the message wrong - otherwise his code wouldn't have even compiled, much less got memory leaks Wink | ;)

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"

Re: memory leak!!!!!!

namaskaaram14-Feb-06 21:34

namaskaaram

14-Feb-06 21:34

.....yeah just tried it out!....ur right! thankz! Smile | :)

hmm,doesnt the location pointed by the pointer gets lost when made null?,so i believe we loose the dynamically created objects location dont we?so there is a mem leak right?;)
anywayz thanx for the correction! Smile | :)

cheerz!

dont want,dont want thinking,climbing on head and jumping grass!
(venda venda ennu vicharikumbol thellayill keyaree chadunnoda pulle!)

Re: memory leak!!!!!!

Ryan Binns14-Feb-06 21:44

Ryan Binns

14-Feb-06 21:44

There is usually a memory leak when you delete NULL. Not always, however. if you have a class that allocates memory using new, it's reasonably standard practice to delete it in the destructor. If you have another cleanup routine that deletes the pointer (and then sets it to NULL - always an excellent idea), then the delete in the destructor doesn't need to have a if (!NULL) check around it - it makes no difference whether the pointer is NULL or not.

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"

Re: memory leak!!!!!!

Ashutosh_shashi14-Feb-06 21:18

Ashutosh_shashi

14-Feb-06 21:18

namaskaaram wrote:
assigning name =NULL and then deleting it will give u an error since u r trying to delete a block that points to the null address!!!!
rather the code should be more like.....

Do you know basic of pointers.........?

Ashutosh

Re: memory leak!!!!!!

ThatsAlok14-Feb-06 23:11

ThatsAlok

14-Feb-06 23:11

namaskaaram wrote:
int main(){char *name = NULL; name = getmestring(); cout<<name<<endl;if(name !="NULL)delete" []="" name;}<="" blockquote="">

change it to

if(name != NULL)
delete [] name;
name=NULL

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

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