C / C++ / MFC

Re: Connect to MySQL from MFC Dlg

19-Dec-07 2:39

QuickDeveloper wrote:
I want to connect to MySQL database when i click a button in MFC dialog based application.

So what are you having trouble with: 1) connecting to the data source, or 2) responding to a button click?

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

QuickDeveloper19-Dec-07 19:07

QuickDeveloper

19-Dec-07 19:07

DavidCrow wrote:
1) connecting to the data source,

Connecting to the datasource while creating DSN

"Every morning I go through Forbes list of 40 richest people in the world. If my name is not in there, I go to work..!!!"

Re: Connect to MySQL from MFC Dlg

David Crow20-Dec-07 2:23

read/write functions with dots as the last parameter

20-Dec-07 2:23

One way is to create a CRecordset-derived object. ClassWizard (Ctrl+W) will ask you what DSN to use.

Anthony Appleyard18-Dec-07 23:49

Anthony Appleyard

18-Dec-07 23:49

This type of construction so that a function with an indefinitely long parameter list can pass those parameterson to another function:

/*-----*/
void diprintf(HWND db,short c,char*fmt,...){char C[256];
vsprintf(C,fmt,(&fmt)+1);
SetDlgItemText(db,c,C);};
/*-----*/
short discanf(HWND db,short c,char*fmt,...){char C[256];
GetDlgItemText(db,c,C,256);
C[255]=0; return vsscanf(C,fmt,(&fmt)+1);}
/*-----*/

worked fine for me under Gnu C++ and Borland 4.5 C++, but my (free version) Visual C++ 2008 refused it with these error messages:

1>c:\2d\ppp_vc\ppp_vc\ppp.cpp(274) : error C2664: 'vsprintf' : cannot convert parameter 3 from 'char **' to 'va_list'
1>c:\2d\ppp_vc\ppp_vc\ppp.cpp(277) : error C3861: 'vsscanf': identifier not found

(plus the expected complaints about having char* instead of WCHAR* .)

I cannot find the info that I need in the online help.

Please what should these two funtions be corrected to for my Visual C++ 2008?

Re: read/write functions with dots as the last parameter

CPallini19-Dec-07 0:09

CPallini

19-Dec-07 0:09

Anthony Appleyard wrote:
cannot find the info that I need in the online help.

See there http://msdn2.microsoft.com/en-us/library/28d5ce15(VS.71).aspx[^]
the sample code looks promising Wink | ;)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: read/write functions with dots as the last parameter

David Crow19-Dec-07 2:43

How to get the choosed menu's caputer?

19-Dec-07 2:43

Anthony Appleyard wrote:
1>c:\2d\ppp_vc\ppp_vc\ppp.cpp(274) : error C2664: 'vsprintf' : cannot convert parameter 3 from 'char **' to 'va_list'

So have you looked at the prototype for vsprintf() to see what it is expecting as arguments? The error messages seems fairly self-explanatory.

vernchen18-Dec-07 23:09

vernchen

18-Dec-07 23:09

I want to get the choosed menu's caputer,then to modifly StatusBar's info.
At Event: OnMenuSelect(UINT nItemID,UINT nFlags,HMENU hSysMenu)
I write
void CMainFrame::OnMenuSelect(UINT nItemID,UINT nFlags,HMENU hSysMenu)
{
CString str;
CMenu* pMainMenu = GetMenu();
CMenu* pSubMenu = pMainMenu-> GetSubMenu(nItemID);
pSubMenu->GetMenuString(nItemID,str,MF_BYCOMMAND);
}
But when compile to the " pSubMenu->GetMenuString(nItemID,str,MF_BYCOMMAND);
" It aways tells me wrong ,I don't know why?help!! thanks!

Re: How to get the choosed menu's caputer?

David Crow19-Dec-07 2:53

Return more than one parameter from a single function

19-Dec-07 2:53

vernchen wrote:
But when compile to the " pSubMenu->GetMenuString(nItemID,str,MF_BYCOMMAND);
" It aways tells me wrong ,I don't know why?

Without an actual error message, neither do we. Roll eyes | :rolleyes:

CodingLover18-Dec-07 22:48

Re: Return more than one parameter from a single function

18-Dec-07 22:48

Hi all,

I have a function that calculated two int values. I call the function only by using a string and calculated those two int values. I want to return that two int values from the function when I call it with a string.

Look at the following function,

bool CharWordCount(string rtf, int& word_count, int& char_count)
{
// Body of the function
// do the processing and find the number of chars and
// number of words of the string
}
<pre>

One of my friend say i can do it as above. using the bool type return value. Can you guys give me a help how to do that.

I appreciate your help all the time...
Eranga Smile | :)

jhwurmbach18-Dec-07 23:18

jhwurmbach

18-Dec-07 23:18

Eranga Thennakoon wrote:
One of my friend say i can do it as above.

Sure.
Assign the values you computed to word_count and char_count, respectivly.

And read a book like "C++ for Dummies" or "C++ in 21 days". Esp. the chapter about giving parameters to functions "per value" and "per reference".

Let's think the unthinkable, let's do the undoable, let's prepare to grapple with the ineffable itself, and see if we may not eff it after all.
Douglas Adams, "Dirk Gently's Holistic Detective Agency"

Re: Return more than one parameter from a single function

CodingLover18-Dec-07 23:26

Re: Return more than one parameter from a single function

18-Dec-07 23:26

jhwurmbach wrote:
Assign the values you computed to word_count and char_count, respectivly.

Yes, that is true and can do that and get values. What I'm asking is can I handle it using a bool operator, as I code on my question. Smile | :)

I appreciate your help all the time...
Eranga Smile | :)

jhwurmbach18-Dec-07 23:30

jhwurmbach

18-Dec-07 23:30

Eranga Thennakoon wrote:
What I'm asking is can I handle it using a bool operator

What do you mean? Your code is not showing the bool operator. That would be:

operator bool() const
{
}

In your example, you assign the values and return a bool. Thats it.

Re: Return more than one parameter from a single function

Nelek18-Dec-07 23:31

Re: Return more than one parameter from a single function

18-Dec-07 23:31

You can handle it as void, as bool or as you want. I.E. if you check the values of word_count and char_count before going out that function you can return FALSE if there was an error or TRUE if all worked good.

Greetings.
--------
M.D.V. Wink | ;)

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
“The First Rule of Program Optimization: Don't do it. The Second Rule of Program Optimization (for experts only!): Don't do it yet.” - Michael A. Jackson

CPallini18-Dec-07 23:56

CPallini

18-Dec-07 23:56

The bool value returned by the function has nothing to do with the assignment of the word_count and char_count parameters.

The function suggested doesn't uses the return value to transfer the required info to the caller, it instead directly access the caller variables to the purpose (the bool return value can be merely used to report if the whole operation succeeded).
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: Return more than one parameter from a single function

CodingLover19-Dec-07 0:16

Re: Return more than one parameter from a single function

19-Dec-07 0:16

Ok, I got the point. Now it is clear to me. Thanks fro all your replays.

I appreciate your help all the time...
Eranga Smile | :)

Nelek18-Dec-07 23:28

Re: Return more than one parameter from a single function

18-Dec-07 23:28

AFAIK you can not return two parameters at once. You can return a structure having more parameters, you can decide which parameter to return through If, elses. But not to return two different parameters in the same return.

What you are making is giving the 2 Ints as reference to your function, so that when you end and come back to the calling point, you will have the values of your counts in the "parent" scope.

void AnyFunction ()
{
   int nChar = 0;
   int nWord = 0;

   string rtf = GetYourString ();

   bool bRet = CharWordCount(rtf, &nWord, &nChar);

   printf ("there are %d words and %d characters in the string", nWord, nChar);
}

what you have to code inside the function CharWordCount () is in the answers of your question of yesterday or 2 days ago.

Greetings.
--------
M.D.V. Wink | ;)

CodingLover18-Dec-07 23:43

Re: Return more than one parameter from a single function

18-Dec-07 23:43

Nelek wrote:
What you are making is giving the 2 Ints as reference to your function, so that when you end and come back to the calling point, you will have the values of your counts in the "parent" scope.

Actually I do this in main function. But still what I'm confusing is that, usage of 'bool'

On my main I do this,

	int word_count = 0;
	int char_count = 0;
	WordCount(strRTF, word_count, char_count);
	printf("\nWords %d Characters %d", word_count, char_count);
<pre>

I appreciate your help all the time...
Eranga Smile | :)

Nelek19-Dec-07 0:24

Re: Return more than one parameter from a single function

19-Dec-07 0:24

As I told above, the bool has no sense in this function, but the possibility to give back a TRUE or FALSE depending on if there is an error or not, or if the parameters have sense or not or whatever else. You can get the bool away and code your function as void without any problem.

Greetings.
--------
M.D.V. Wink | ;)

Hamid_RT19-Dec-07 1:33

Hamid_RT

19-Dec-07 1:33

Why you didnt use of a structure for return value?

Re: Return more than one parameter from a single function

CPallini19-Dec-07 2:17

CPallini

19-Dec-07 2:17

Generally speaking that isn't a good idea: it is inefficient.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: Return more than one parameter from a single function

David Crow19-Dec-07 3:00

19-Dec-07 3:00

Eranga Thennakoon wrote:
One of my friend say i can do it as above. using the bool type return value.

Get a new friend that knows a bool is only 1 byte in size, thus can only hold a value of 256 (assuming unsigned). Either that or only plan on counting 128 words and 128 characters.

vc++ to actionscript

aravindakumar18-Dec-07 22:31

aravindakumar

18-Dec-07 22:31

how can i call the actionscript function using vc++.

Re: vc++ to actionscript

Nelek18-Dec-07 22:39