Re: datatransfer - C / C++ / MFC Discussion Boards

how will i be able to transfer data present in a dialog to a listbox in another dialog????

Raja

If (I assume you want to transfer data between dialogs of the same application) your dialogs are modal then you have to copy first dialog's data to some variable (or array of) and then fill the list box of the second dialog using the copied data.
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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

yes the dialogs are of the same application and i get the error of undeclaredvariable in the second dialog,what should be done???

Raja

Mohanraj D wrote:
what should be done???

Post the code.
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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

str="data";
 datatransfer on;
on.DoModal();

and this the listbox in another dialog box

List.AddString(str);

error C2065: 'str' : undeclared identifier
and i have included the header of the firstdlg in seconddlg

Raja

The scope of str must extend to both the dialogs (i.e. you can make it global or, better you may declare it in the parent window class (and the latter should provide accessor methods to).
Anyway, please have a look at this good (but underrated) toxxct's article [^].
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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

is there anyother methods to do datatransfer,how is a globalvariable declaration done???

Raja

I strogly suggest you following the toxcct's article approach.

Anyway, using the global variable approach is simple:
(1) declare, in a common included header file, the variable as extern.
(2) define the variable only in one source file.

For instance, in your main header file (let's assume it is YourApp.h)

extern CString g_MyString; // declaration as extern

and in the main source file, and only there (let's assume again it is YourApp.cpp)

CString g_MyString; // definition

Now you can use g_MyString in any *.cpp file that includes the main header file (i.e. YourApp.h).

You may find a working example of global variable in your sources, since Visual Studio generates code for the global variable theApp.
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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

mmm, nice shortcut.

I had it defined in only one cpp as you said, but I was using "extern type var" everywhere I wanted to use it Blush | :O

Thanks for the trick Roll eyes | :rolleyes:

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--------
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ok,thank u

Raja

ok thank u

Raja

Another way would be to store your application related information in the registry or in an ini file.

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP

Mohanraj D wrote:
error C2065: 'str' : undeclared identifier

The error message tells it all. You have failed to declare str. Should be:

CString str = "data;

But that does nothing to solve your original problem. Before calling DoModal(), you need to populate some variable that belongs to your datatransfer class (e.g., array, list, vector). You can either do this by accessing the variable directly, or implement some sort of "setter" method. Then in the OnInitDiaog() method of datatransfer, populate the listbox with the data.

"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

You can use like this code(If we suppose first dialog is CMain) on the target:
CMain* m_Main=(CMain*)GetParent();
m_main->m_Litsbox

I wrote a short code to write the status of my program to a file, but when debug in that code, I realize that fwrite function still increase its file pointer but when I read that file by fread function, I can't read that value. This is my code:

// TODO: Add your control notification handler code here
//write config file
FILE *fout = fopen( "config.pcm", "wb" );

if ( fout )
{
//write the time of power function
fwrite( &m_uTime, sizeof( int ), 1, fout );

unsigned long temp;
//write tasks
//number of day task
temp = m_alltasks.size();
fwrite( &temp, sizeof( long ), 1, fout );

for ( int i = 0; i < m_alltasks.size(); i++ )
{
//date
fwrite( &m_alltasks[i].date, sizeof( MYDATE ), 1, fout );

//number of notes in that day
temp = m_alltasks[i].tasks.size();
fwrite( &temp, sizeof( long ), 1, fout );

//notes
for ( int j = 0; j < m_alltasks[i].tasks.size(); j++ )
{
fwrite( &m_alltasks[i].tasks[j], sizeof( TASK ), 1, fout );
}
}

//how many hotkeys have been defined
temp = m_hkArr.size();

fwrite( &temp, sizeof( long ), 1, fout );

//write the list of hotkeys

for ( int i = 0; i < temp; i++ )
fwrite( &m_hkArr[i], sizeof( HOTKEY ), 1, fout );

fclose( fout );
}
else
{
MessageBox( _T( "Can't write config file" ), _T( "Warning" ) );
OnCancel();
}

//unregister hotkeys
for ( int i = 0; i < m_hkArr.size(); i++ )
{
UnregisterHotKey( m_hWnd, m_hkArr[i].id );
GlobalDeleteAtom( m_hkArr[i].id );
}

OnCancel();

They all work except for the code I bolded ( file pointer still increase, but the file is not change )... Help me plz >.<...

How did you check the file was not actually written?
How did you define m_hkArr?
How was HOTKEY defined?
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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

I do it on Visual Studio 2005 SP1. I added config.pcm into my solution. After I had run my program, if config.pcm changed the content, then Visual Studio would ask you to update the content of that file. When I debug, I see the file pointer increase, but after I closed fout, VS didn't ask me to update the content -> the content hadn't been modified. m_hkArr is vector <hotkey> m_hkArr. The structure of struct HOTKEY:
struct HOTKEY
{
BOOL isCtrl;
UINT c;
TCHAR szPath[256];
int id; //id of this hot key
};

This struct is self-identified Hotkey Big Grin | :-D

. I just check for Ctrl or Alt is press with the key. id is the ID of the hotkey, return value of GlobalAddAtom. The code I have posted just a bit of my code

Are you sure you're writing to the same file that is open by Visual Studio?

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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

yes, When I change the config of my program, so, it have to write in the config.pcm. All the configurations of my program are written on config.pcm except for the hotkeys ( the bolded code )

How can you see the file pointer advancing? How many HOTKEY items did you successfully write (i.e. Did you check temp value? Did you check fwrite return value?)?
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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

when debuging, just watch for the file pointer, so, I can see fout increase the value, I write 1 or 2 HOTKEY to try, but the content no change. When I read the file, the value is 0 >.<

Cadimi wrote:
I write 1 or 2 HOTKEY to try

But then do you close the file?

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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

as you can see in the code, I closed it, and before closed it, I fflush( fout ) carefully Big Grin | :-D

Yes, I saw the code, anyway I was referring to you debugging actions (i.e. I didn't know if you stopped the program after few write operations).
The reason behind my questions is I cannot believe fwrite silently failing, it never happened to me.
Can't you isolate the failing piece of the writing routine and run it in a simpler context (for instance another, adhoc, project)?

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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

thanks for your help, that's the worse thing I've ever met >.<