C / C++ / MFC Discussion Boards

Re: Unditable combobox via code

hariakuthota23-Jul-08 9:11

hariakuthota

23-Jul-08 9:11

tried but thats not working properly...

Re: Unditable combobox via code

CPallini23-Jul-08 9:30

CPallini

23-Jul-08 9:30

Possible you've to try better.
Smile | :)

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-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
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[My articles]

Re: Unditable combobox via code

JudyL_MD23-Jul-08 10:10

JudyL_MD

23-Jul-08 10:10

As CPallini implies, the function does work correctly. You've done something wrong.

What does "it doesn't work" mean - with no code, we can't guess. Does the string you're trying to set exist in the second combo box?

Judy

Re: Unditable combobox via code

hariakuthota23-Jul-08 8:43

hariakuthota

23-Jul-08 8:43

I dont want to use the dropdownlist because in my application based on the combobox selection another combo box has to be populated with the first combobox seleted item.

EX: if i click "alphabets"
i have to set the other combobox to this value,
and i am not able to use the m_combobox2.setwindowtext() and also
SetDlgItemText(idc_combobox2,"string"); if i use the dropdownlist

Run time error when ticked the option "owner draw" for a button

hariakuthota23-Jul-08 6:53

hariakuthota

23-Jul-08 6:53

Hi i am new to the concepts of mfc..
in my application i want to change the backgroung color of the button through ctlcolor for that i am ticking the option owner draw for the button.when i try to run the application i am getting abort error..
can anybody please suggest me the reason for this???

Thanks in advance...

Re: Run time error when ticked the option "owner draw" for a button

CPallini23-Jul-08 6:56

CPallini

23-Jul-08 6:56

hariakuthota wrote:
can anybody please suggest me the reason for this???

The debugger can (for free!).
Smile | :)

Re: Run time error when ticked the option "owner draw" for a button

Luc Pattyn23-Jul-08 7:11

Luc Pattyn

23-Jul-08 7:11

CPallini wrote:
The debugger can (for free!)

Who is that guy? Does he make house calls?

Smile | :)

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Voting for dummies? No thanks. Dead | X|

Re: Run time error when ticked the option "owner draw" for a button

CPallini23-Jul-08 7:13

CPallini

23-Jul-08 7:13

Luc Pattyn wrote:
Who is that guy?

Girl my friend, girl. And it's lovely to have a break with her (or simply a watch).
Big Grin | :-D

Re: Run time error when ticked the option "owner draw" for a button

Luc Pattyn23-Jul-08 8:04

Luc Pattyn

23-Jul-08 8:04

Aha. That could be the reason why people tend to spend so much time debugging...

But then I wonder why they ask for help on sites like this one Confused | :confused:

Luc Pattyn [Forum Guidelines] [My Articles]

Voting for dummies? No thanks. Dead | X|

Re: Run time error when ticked the option "owner draw" for a button

CPallini23-Jul-08 9:26

CPallini

23-Jul-08 9:26

Possibly because girls drive you crazy, after a while...
Big Grin | :-D

how to truncate a string based on buffer size.

Nandu_77b23-Jul-08 6:26

Nandu_77b

23-Jul-08 6:26

Can any one help me to truncate the string based on the buffer size, for the below show scenario.

main()
{
int size = 50;
char errmsg [size];
get_last_error( errmsg, size );
cout<<errmsg;

}

get_last_error( char *errmsg, int bufsize )
{
string sErrMsg;

if ( sErrMsg.capacity() > bufsize )
{
// here i want to truncate the string, so that the size of string will fit into "bufsize". Then copy the string to errmsg
// strcpy( errmsg, sErrMsg.c_str() );
// how to truncate the string based on given buffersize
// so that we can atlest copy the possible string to errmsg if not the whole string
}
else
{
strcpy( errmsg, sErrMsg.c_str() );
*errcode = nErrCode;
}
}

Re: how to truncate a string based on buffer size.

David Crow23-Jul-08 6:30

David Crow

23-Jul-08 6:30

Nandu_77b wrote:
// how to truncate the string based on given buffersize

How about the substr() method?

"Love people and use things, not love things and use people." - Unknown

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

Re: how to truncate a string based on buffer size.

Nandu_77b23-Jul-08 6:42

Nandu_77b

23-Jul-08 6:42

Nandu_77b wrote:
// how to truncate the string based on given buffersize

How about the substr() method?

substr() this fun will not take buffer size, it takes length of characters. I need to truncate based on buffer size. Please see my code which will give you clear idea.

-Nandu

Re: how to truncate a string based on buffer size.

David Crow23-Jul-08 7:25

David Crow

23-Jul-08 7:25

If the size of your buffer is 50, then you would extract characters 0-49.

"Love people and use things, not love things and use people." - Unknown

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

Re: how to truncate a string based on buffer size.

CPallini23-Jul-08 6:55

CPallini

23-Jul-08 6:55

What about strncpy [^]?
Smile | :)

Re: how to truncate a string based on buffer size.

Nandu_77b23-Jul-08 7:05

Nandu_77b

23-Jul-08 7:05

strncpy() will also take char length not the buffersize.

- Nandu

Re: how to truncate a string based on buffer size.

Nandu_77b23-Jul-08 7:06

Nandu_77b

23-Jul-08 7:06

--strncpy() will also take char length not the buffersize.

- Nandu

Re: how to truncate a string based on buffer size.

CPallini23-Jul-08 7:20

CPallini

23-Jul-08 7:20

Are you aware that, for ANSI strings, the char length and the buffer size (bytes) are basically the same?
Smile | :)

Re: how to truncate a string based on buffer size.

Nandu_77b23-Jul-08 10:09

Nandu_77b

23-Jul-08 10:09

Yes you are correct,

Thanks
Nandu

Re: how to truncate a string based on buffer size.

Joe Woodbury23-Jul-08 12:55

Joe Woodbury

23-Jul-08 12:55

lstrcpynA(errmsg, bufsize);

If using TCHAR, do:

<br />
lstrcpyn(errmsg, bufsize / sizeof(TCHAR));

(lstrcpyn is a tiny bit more efficient than strncpy since it doesn't fill the rest of the buffer with zeros after completing the copy. With large buffers, this is generally a waste of cycles.)

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

ToolBar Switching

Nuri Ismail23-Jul-08 5:56

Nuri Ismail

23-Jul-08 5:56

Hi,
I have created an SDI application with tabbed view. I have used view class derived from CTabView (class from MFC Feature Pack). I want to show different toolbars on the MainFrame for each tab and alternately change the toolbars when the tab selection is changed. But i have problems with swithching the toolbars. Is there any way to switch the toolbars or associate a custom toolbar for each tab of the view?

Thanks

Static variable

AnithaSubramani23-Jul-08 4:52

AnithaSubramani

23-Jul-08 4:52

Dear All,

I have two classes Test and Test1. I have a static variable in the class Test and I have to access it in another class Test1 from a funtion. When I access it, I got linker error. The error is :

1>Test1.obj : error LNK2001: unresolved external symbol "public: static int Test::cnt" (?cnt@Test@@2HA)
1>Test.obj : error LNK2001: unresolved external symbol "public: static int Test::cnt" (?cnt@Test@@2HA)

Code snippet :

//First class
class Test : public CDialog,public CDemux
{
	DECLARE_DYNAMIC(DecodeTS)
	//DECLARE_DYNAMIC(TSAnalyzerDlg)
Public
	static int cnt;

.......

//Second class function
void Test1::GetData()
{
int cnt =Test::cnt;
}

Re: Static variable

Alan Balkany23-Jul-08 5:02

Alan Balkany

23-Jul-08 5:02

This is a known quirk in C++: For static variables in a class, you need to repeat the declaration in the .cpp file.

So add this:

int Test1::cnt;

to your .cpp file and it will stop this linker error.

Re: Static variable

AnithaSubramani23-Jul-08 5:27

AnithaSubramani

23-Jul-08 5:27

I have the static variable in Test class. When I declare again in Test.cpp it shows redefinition error. I do like this in Test.cpp file.

int Test::cnt;

Linker error gone but another error occur as redefinition.

Re: Static variable

AnithaSubramani23-Jul-08 5:33

AnithaSubramani

23-Jul-08 5:33

Hello Alan,

Now I have fixed it, the problem is that I give the int Test::cnt; in the constructor and thats why the error I got. Now I give the line at the top of the cpp file and it is working fine.

Thank you very much.

Many thanks.

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