error LNK2019: unresolved external symbol - C / C++ / MFC Discussion Boards

Re: SetFont and TrackSelect Property of TreeCtrl not working together.

Le@rner1-Jan-09 17:25

Le@rner

1-Jan-09 17:25

Thanks

IN A DAY, WHEN YOU DON'T COME ACROSS ANY PROBLEMS - YOU CAN BE SURE THAT YOU ARE TRAVELLING IN A WRONG PATH

Problem Allocating the string?

Dark_eye31-Dec-08 21:52

Dark_eye

31-Dec-08 21:52

Hello all, first of all, happy holidays.
I have the following function to encode a file to a base64 string:

string FileToBase64 (string path)
{
ifstream myFile (path.c_str(), ios::in | ios::binary);
int size = FileSize(path);
char buffer[size];
string b64;

if ( myFile.read ( buffer, size ) )
{
     b64 = base64_encode( reinterpret_cast<const unsigned="">(buffer), size );
}
return b64;     
}</const>

So I call it with:

string enc = FileToBase64("C:\\music.mp3");

With small files worked ok, but this is around 5,6 MB.
And with that file, my App Crashed, and the debugger gave me an error in new_allocator.h line 62, thats is:

new_allocator() throw() { }

I supose, the string type has a limit of capacity, but if this is true, what can I do?
Is there a type like Longtext in mySQL?

Thanks in advantage.

Re: Problem Allocating the string?

«_Superman_»31-Dec-08 22:24

«_Superman_»

31-Dec-08 22:24

Perhaps you could try to change the function signature to be called as

<br />
string enc;<br />
FileToBase64("C:\\music.mp3", enc);<br />

« Superman »

Re: Problem Allocating the string?

Dark_eye1-Jan-09 1:10

Dark_eye

1-Jan-09 1:10

I think, the problem it will be there anyway, becouse changing the function siganture, will not avoid doing this:

string x = VERY LONG BASE64 STRING

It is not true? D'Oh! | :doh:

Re: Problem Allocating the string?

Jijo.Raj1-Jan-09 1:44

Jijo.Raj

1-Jan-09 1:44

Exactly at where does your application crash? Could you post the call stack and exact line? My findings are as follows.

Dark_eye wrote:
int size = FileSize(path);
char buffer[size];

You are allocating the buffer for the entire file on stack. For a file for 5.6 MB you are allocating that much on stack. Believe me, stack is precious! Wink | ;)

1) Allocate the buffer by using new.

char* buffer = new char[size];

2) if you get error while manipulating strings, then try using std::rope[^] which can withstand heavy strings. I guess, std::rope is not yet avaiable with visual studio STL implementation and you've to use STLPort[^] for that.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: Problem Allocating the string?

Dark_eye1-Jan-09 9:32

Dark_eye

1-Jan-09 9:32

Oh thanks!!!!
Changing

char buffer[size];

to char* buffer = new char[size];

solved the problem.

Also the std::rope solution sounds very interesting, that is exactly what I was thinking when I said "something like Longtext in MySQL". And I use Dev-Cpp so, no problem with VC Poke tongue | ;-P

Happy holidays to all the people in CodeProject Big Grin | :-D

Re: Problem Allocating the string?

Luc Pattyn1-Jan-09 4:15

Luc Pattyn

1-Jan-09 4:15

Hi,

my guess is you exceed your stack limit.
Solution: use a heap-based buffer instead of a stack-based one; it takes a bit more code to do so,
but then the buffer size will be limited to available heap space.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Love, happiness and fewer bugs for 2009!

error LNK2019: unresolved external symbol

zhiyuan1631-Dec-08 21:37

zhiyuan16

31-Dec-08 21:37

dear all

what is problem the following? thanks a lot.

.\AVI Player.cpp(53) : warning C4996: 'CWinApp::Enable3dControls': CWinApp::Enable3dControls is no longer needed. You should remove this call.
        D:\All Install Application\VC\atlmfc\include\afxwin.h(4818) : see declaration of 'CWinApp::Enable3dControls'
Generating Code...
Compiling resources...
Microsoft (R) Windows (R) Resource Compiler Version 6.0.5724.0
Copyright (C) Microsoft Corporation.  All rights reserved.
Linking...
AVI PlayerDlg.obj : error LNK2019: unresolved external symbol _MCIWndCreateA referenced in function "protected: void __thiscall CAVIPlayerDlg::OnPlay(void)" (?OnPlay@CAVIPlayerDlg@@IAEXXZ)
.\Release/AVI Player.exe : fatal error LNK1120: 1 unresolved externals
Build log was saved at "file://c:\Documents and Settings\ZhiYuan Li\Desktop\MP3Player\Release\BuildLog.htm"
AVI Player - 2 error(s), 1 warning(s)
========== Rebuild All: 0 succeeded, 1 failed, 0 skipped

Re: error LNK2019: unresolved external symbol

«_Superman_»31-Dec-08 21:41

«_Superman_»

31-Dec-08 21:41

Try giving this at the beginning of the file

<br />
#pragma comment( lib, "Vfw32" )<br />

« Superman »

Re: error LNK2019: unresolved external symbol

zhiyuan1631-Dec-08 21:55

zhiyuan16

31-Dec-08 21:55

which file beginning? i put vfw.h already in my file. thanks

Re: error LNK2019: unresolved external symbol

zhiyuan1631-Dec-08 22:14

zhiyuan16

31-Dec-08 22:14

before posted first one, i already put it, now still same problem,thanks

Re: error LNK2019: unresolved external symbol

«_Superman_»31-Dec-08 22:21

«_Superman_»

31-Dec-08 22:21

That command is not for the .h file.
It is for the .lib file.
That is the unresolved error that you get.

« Superman »

Expand and Collpse Tree on Click of Enter key.

Le@rner31-Dec-08 20:41

Le@rner

31-Dec-08 20:41

Hi all,

i have a CTreeCtrl,i have handle working of enter key on WM_KEYDOWN function.

i want i i press the enter key and tree is collapse than it will be expand and if it is already expanded than it is collapsed.

i m also try Expand function of TreeCtrl but its not perfectly works.

please tell me how can i do this.

thanks in advance.

IN A DAY, WHEN YOU DON'T COME ACROSS ANY PROBLEMS - YOU CAN BE SURE THAT YOU ARE TRAVELLING IN A WRONG PATH

Re: Expand and Collpse Tree on Click of Enter key.

Jijo.Raj1-Jan-09 12:27

Jijo.Raj

1-Jan-09 12:27

You can expand/collapse the tree nodes by pressing the +/- keys. So for mimicking the same behavior for Enter key, override the PreTranslateMessage() of your dialog and handle all keydown messages for your tree control. If the current item is expanded assign the keycode as VK_SUBTRACT to collapse and if its collapsed assign the keycode as VK_ADD to expand. Check the code snippet below.

BOOL CRabbitDlgDlg::PreTranslateMessage(MSG* pMsg) 
{
    // Check whether its a keypress.
    if( pMsg->message == WM_KEYDOWN )
    {
        // Check whether its for our tree control.
        UINT CtrlId = ::GetDlgCtrlID( pMsg->hwnd );
	    if( CtrlId == IDC_TREECTRL )
	    {
            // Check whether its enter key.
            if( pMsg->wParam == VK_RETURN)
            {
                // Check whether the currently selected item is 
                HTREEITEM CurrentItem = m_TreeCtrl.GetSelectedItem();
                if( m_TreeCtrl.GetItemState( CurrentItem, TVIS_EXPANDED ) & TVIS_EXPANDED )
                {
                    // Current Item is Expanded. So send - Key code to collapse it.
                    pMsg->wParam = VK_SUBTRACT;
                }
                else
                {
                    // Current Item is Collapsed. So send + Key code to Expand it.
                    pMsg->wParam = VK_ADD;
                }
            }
        }
	}
	
	return CDialog::PreTranslateMessage(pMsg);
}

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: Expand and Collpse Tree on Click of Enter key.

Le@rner1-Jan-09 17:25

Le@rner

1-Jan-09 17:25

Thanks.

IN A DAY, WHEN YOU DON'T COME ACROSS ANY PROBLEMS - YOU CAN BE SURE THAT YOU ARE TRAVELLING IN A WRONG PATH

Can Debugger show the values in binary form?

Joseph Marzbani31-Dec-08 20:04

Joseph Marzbani

31-Dec-08 20:04

I'm using VC++.NET and I wonder if Its debugger can show the values in binary form or not? By now I can see the variables only in dec and hex forms.

Thank you masters!

Re: Can Debugger show the values in binary form?

Nibu babu thomas31-Dec-08 23:09

Nibu babu thomas

31-Dec-08 23:09

Jusef Marzbany wrote:
I'm using VC++.NET and I wonder if Its debugger can show the values in binary form or not? By now I can see the variables only in dec and hex forms.

No in my knowledge. You can use windows calculater to to get binary form of a number, I do find it quite useful particularly for masking bits.

Nibu babu thomas
Microsoft MVP for VC++

Code must be written to be read, not by the compiler, but by another human being.

Programming Blog: http://nibuthomas.wordpress.com

Re: Can Debugger show the values in binary form?

Jijo.Raj1-Jan-09 9:26

Jijo.Raj

1-Jan-09 9:26

Jusef Marzbany wrote:
I wonder if Its debugger can show the values in binary form or not?

Your question inspired me to write this - How to Watch Variables in Binary by using Visual Studio Debugger?[^]. Big Grin | :-D

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: Can Debugger show the values in binary form?

CPallini1-Jan-09 9:33

CPallini

1-Jan-09 9:33

Great.

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

[My articles]

Re: Can Debugger show the values in binary form?

Jijo.Raj1-Jan-09 9:59

Jijo.Raj

1-Jan-09 9:59

Thanks Man! Big Grin | :-D

And Happy New Year!!!

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: Can Debugger show the values in binary form?

CPallini1-Jan-09 10:32

CPallini

1-Jan-09 10:32

Happy new year to you!!! Big Grin | :-D

Application working fine but seems like system has hanged

VCProgrammer31-Dec-08 20:01

VCProgrammer

31-Dec-08 20:01

Hi all,

I have made a dialog based application in vc2008....

I have made a worker thread inside my application, now my problem is when I execute my application everything is running fine but my dialog box start displaying not responding and it looks like system is hanged but after few mintues it displays right output.....

Like everything working fine in background......

I am not getting what is the problem.......

Can anybody tell me how to resolve the problem....

Thanks in advance....

Re: Application working fine but seems like system has hanged

Joseph Marzbani31-Dec-08 20:14

Joseph Marzbani

31-Dec-08 20:14

give us a little more information on what your App is and what you want the working thread to do. (Always do so)

Thank you masters!

Re: Application working fine but seems like system has hanged

Jijo.Raj1-Jan-09 0:13

Jijo.Raj

1-Jan-09 0:13

VCProgrammer wrote:
I have made a worker thread inside my application, now my problem is when I execute my application everything is running fine but my dialog box start displaying not responding and it looks like system is hanged but after few mintues it displays right output.....

Are you doing any lengthy background operation in UI thread? Which ultimately makes your UI freeze. In that case, spawn a new thread and do your background operations there which will make the UI responsive.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

checkbox in List control and image

vicky0000031-Dec-08 18:32

vicky00000

31-Dec-08 18:32

Hi all,

I used a list control with check box, and image list.
My aim is check box is in first column and image in second column.
I did as i want.. but one problem is
first image in image list is shown in first column along with check box?
I need to check box alone in first column..

Thanks a lot.

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