Re: How to change CDocument Variables from within the CWinApp derived Class? - C / C++ / MFC Discussion Boards

Re: Setting (+) for Tree Item even if there are no children under the item.

PJ Arends15-Nov-05 11:15

15-Nov-05 11:15

Check out the TVITEM::cChildren member, specifically the I_CHILDRENCALLBACK flag.

Causes the control to use the TVN_GETDISPINFO notification message to check whether the '+' needs to be displayed or not.

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

"Obviously ??? You're definitely a superstar!!!" - mYkel - 21 Jun '04

"There's not enough blatant self-congratulatory backslapping in the world today..." - HumblePie - 21 Jun '05

Within you lies the power for good - Use it!

Re: Setting (+) for Tree Item even if there are no children under the item.

Maximilien15-Nov-05 13:00

Maximilien

15-Nov-05 13:00

Thank you both ( David and PJ ) I will look at this tomorrow morning .

Maximilien Lincourt
Your Head A Splode - Strong Bad

How to change CDocument Variables from within the CWinApp derived Class?

Franken15-Nov-05 8:56

Franken

15-Nov-05 8:56

Hi,

I've written an application (SDI), which runs a thread in my derived CWinApp class. The thread is mainly for collecting data from a RS232 Interface. Sometimes I want to assign parts of this data to variables in my document class (for storing and displaying).

How can I adress these variables?

I know that it somehow works with the DocTemplate pointer m_pDocManager->GetFirstDocTemplatePosition() but I don't know the correct syntax. Can anybody give me a short introduction?

Thanks for your help.

Re: How to change CDocument Variables from within the CWinApp derived Class?

David Crow15-Nov-05 10:09

David Crow

15-Nov-05 10:09

The document can be accessed from anywhere like:

AfxGetMainWnd()->GetActiveDocument();

It can be accessed from the main application object like:

GetMainWnd()->GetActiveDocument();

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: How to change CDocument Variables from within the CWinApp derived Class?

Franken15-Nov-05 23:29

Franken

15-Nov-05 23:29

Thanks for your help. But I still have a problem. GetActiveDocument() is not a member of CWnd. With GetMainWnd() I can only access GetActiveWindow(). What is my mistake? Do I have to do a type cast? I've tried the following:

CFrameWnd* pFrame = (CFrameWnd*)GetMainWnd();<br />
CMyDocument* pDoc = (CMyDocument*)pFrame->GetActiveDocument();<br />
pDoc->myVariable = myValue;

With this code I don't get a compile error but a runtime error;

Re: How to change CDocument Variables from within the CWinApp derived Class?

David Crow16-Nov-05 2:43

David Crow

16-Nov-05 2:43

Franken wrote:
GetActiveDocument() is not a member of CWnd.

Right, it's part of the frame.

Franken wrote:
With GetMainWnd() I can only access GetActiveWindow().

Not necessary in this case.

Franken wrote:
With this code I don't get a compile error but a runtime error;

Which is?

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: How to change CDocument Variables from within the CWinApp derived Class?

Franken15-Nov-05 23:47

Franken

15-Nov-05 23:47

Now it works Smile | :)

somehow. The runtime error only occur if I try to place this code in the worker thread, not if it is placed somewhere else in the main application class. But I think I can find a solution for that.

Thanks.

Re: How to change CDocument Variables from within the CWinApp derived Class?

David Crow16-Nov-05 3:10

David Crow

16-Nov-05 3:10

Franken wrote:
Now it works somehow.

This is usually a good indication that the problem still exists and has simply been masked or moved to a new location.

Franken wrote:
The runtime error only occur if I try to place this code in the worker thread,

Which makes sense as worker threads shouldn't be accessing such information. See these two articles for more on threads and how they are supposed to communicate back and forth with the primary thread.

http://www.flounder.com/workerthreads.htm

http://www.flounder.com/uithreads.htm

"Take only what you need and leave the land as you found it." - Native American Proverb

error LNK2001: unresolved external symbol

celllllllll15-Nov-05 6:53

celllllllll

15-Nov-05 6:53

Hi All,

Can you guys please help me resolving this error?

Thanks in advance

Preeti9

Re: error LNK2001: unresolved external symbol

David Crow15-Nov-05 7:20

David Crow

15-Nov-05 7:20

You've not provided enough information. See here for possibilities.

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: error LNK2001: unresolved external symbol

celllllllll15-Nov-05 7:31

celllllllll

15-Nov-05 7:31

Sorry for not providing enough info...

Here are the errors listed:
[code]
Linking...
MSVCRT.lib(MSVCRT.dll) : error LNK2005: __vsnprintf already defined in LIBCMT.lib(vsnprint.obj)
MSVCRT.lib(MSVCRT.dll) : warning LNK4006: __vsnprintf already defined in LIBCMT.lib(vsnprint.obj); second definition ignored
Creating library ReleaseMinSize/WosaIDC.lib and object ReleaseMinSize/WosaIDC.exp
LINK : warning LNK4098: defaultlib "MSVCRT" conflicts with use of other libs; use /NODEFAULTLIB:library
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFSClose@4
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFSDeregister@12
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFMSetTimer@16
CardReaderEvent.obj : error LNK2001: unresolved external symbol _WFMSetTimer@16
CardReaderOper.obj : error LNK2001: unresolved external symbol _WFMSetTimer@16
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFSRegister@12
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFMSetTraceLevel@8
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFSOpen@36
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFMKillTimer@4
CardReaderEvent.obj : error LNK2001: unresolved external symbol _WFMKillTimer@4
CardReaderOper.obj : error LNK2001: unresolved external symbol _WFMKillTimer@4
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFSFreeResult@4
CardReaderEvent.obj : error LNK2001: unresolved external symbol _WFSFreeResult@4
CardReaderOper.obj : error LNK2001: unresolved external symbol _WFSFreeResult@4
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFSExecute@20
CardReaderDev.obj : error LNK2001: unresolved external symbol _WFSGetInfo@20
CardReaderOper.obj : error LNK2001: unresolved external symbol _WFSCancelAsyncRequest@8
CardReaderOper.obj : error LNK2001: unresolved external symbol _WFSAsyncExecute@24
CardReaderReg.obj : error LNK2001: unresolved external symbol _WFMCloseKey@4
CardReaderReg.obj : error LNK2001: unresolved external symbol _WFMQueryValue@16
CardReaderReg.obj : error LNK2001: unresolved external symbol _WFMSetValue@16
CardReaderReg.obj : error LNK2001: unresolved external symbol _WFMCreateKey@16
CardReaderReg.obj : error LNK2001: unresolved external symbol _WFMOpenKey@12
LIBCMT.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
ReleaseMinSize/WosaIDC.dll : fatal error LNK1120: 18 unresolved externals
Error executing link.exe.

WosaIDC.dll - 26 error(s), 2 warning(s)
[\code]

I have included all the lib files also..But still I am getting 26 errors.

Thanks again

Preeti9

Re: error LNK2001: unresolved external symbol

tranglt15-Nov-05 18:55

tranglt

15-Nov-05 18:55

Dear u!
do you use Visual C++ 6.0?
you set again Option setting.
Project/Setting/ Link ..
I Hope that is useful to you!
Best regards.

-- modified at 0:56 Wednesday 16th November, 2005

Re: error LNK2001: unresolved external symbol

sunit515-Nov-05 20:18

sunit5

15-Nov-05 20:18

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/lnk2001.asp

database schema design question

ppp00115-Nov-05 6:43

ppp001

15-Nov-05 6:43

Hi,

I have two objects, both point to each other in OO.
e.g.
Class Father
{
private int id; //id of father
private Son son;
}
Class Son
{
private int id; //id of Son
private Father father;
}

so I need to have two tables in database as follow,

Table Father :
(id, SonId)

Table Son :
(id, FatherId)

The problem is, should I eliminate the one of the reference in one of the table, e.g.

Table Father :
(id)

Table Son :
(id, FatherId)

so I just have the fatherID in the son table.
But if I remove the sonID from the father table,
I need to join the two tables when I retrieve fathers
from the father table.
So what are the pros and cons of the two schema design ?

Thanks

Re: database schema design question

Mayur Mahajan15-Nov-05 14:36

Mayur Mahajan

15-Nov-05 14:36

If you keep the references in both the tables, you can improve the efficiency by eliminating joins. You can find all 'children' of a 'father' and vice versa by a simple query on a single table.
The down side however is an additional overhead in maintaining the redundant data consistently. You need to make sure to update the respective fields whenever any child is to be deleted or the other way. Just see what is preferable for your application, efficiency or simplicity...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

do not show MFC Window

inf00915-Nov-05 6:30

inf009

15-Nov-05 6:30

I am trying that my program does some task before calling MFC class:

#include <afxwin.h>

class MFC_Window :public CFrameWnd
{
public:
MFC_Window()
{
Create(NULL,_T("whatever"));
}
};

class MyApp :public CWinApp
{
MFC_Window *wnd;
public:
BOOL InitInstance()
{
wnd = new MFC_Window();
m_pMainWnd = wnd;
m_pMainWnd->ShowWindow(1);
return 1;
}
};

int main ()
{
// some tasks...

if (some tasks == true) MyApp theApp;
}

Calling MFC from main() does not work. Does anybody know how to do this? Or how to put the MFC as not visible?

Thanks,
Christian

Re: do not show MFC Window

David Crow15-Nov-05 7:18

David Crow

15-Nov-05 7:18

Just for clarity, MFC is not a class nor is it callable.

What exactly is it that you are wanting to do prior to displaying any sort of window?

Deriving from CFrameWnd indicates that you are working on an application. Thus you'll not be able to use main().

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: do not show MFC Window

__yb15-Nov-05 10:56

__yb

15-Nov-05 10:56

If I understand u correctly u want to do things before showing the main window.
To do this u don't have to mangle with main(), WinMain() nor constructing MyApp yourself. All u have to do is put some code in MyApp::InitInstance() before the window creation/show.

Just to comment few other things:
First, the way u try to initialize MyApp is invalid syntax.
If u follow the MFC App Wizard, MyApp is created on the "global stack" - the standard library initializes it before calling main().
Second, u can track down MFC's WinMain (just look at the call stack) and alter it. But your code will not run there unless u compile MFC itself.

HTH

Re: do not show MFC Window

inf00916-Nov-05 6:13

inf009

16-Nov-05 6:13

Thank you for your replies.

Yes, what I am trying to do is to do things before showing the main window, or not to show it at all. My programm enumerates NFC boards, and if it detects more than 1, a window should pop up and ask user to select one of them. If it only finds one board, the app should select that board and the window shouldnt pop up.

I tried to set the visible property to false, but nothing happened!?!? The only thing I can imagine is that the release build wont show the window, I dont know and didnt try it.

Thanks

DrawText !!

hatemtaleb15-Nov-05 6:24

hatemtaleb

15-Nov-05 6:24

Hi everybody,
I'am using the DrawText function to draw this text "p&m":
DrawText(_T("p&m"),LPRECT(CRect(0,0,100,100)),DT_LEFT);
but my problem is that the text on the screen appear with the 'm' underlined.

could someone help me!!

thanks.

Re: DrawText !!

Mike Dimmick15-Nov-05 6:30

Mike Dimmick

15-Nov-05 6:30

Either double the & character, or use the DT_NOPREFIX flag (i.e. specify DT_LEFT | DT_NOPREFIX).

This feature is intended for use by various Windows functions to indicate accelerator keys for activating controls. Windows 2000 and higher, by default, hide the accelerator key indicators until the Alt key is pressed, so you may not have seen this behaviour.

Stability. What an interesting concept. -- Chris Maunder

Re: DrawText !!

mikanu15-Nov-05 6:31

mikanu

15-Nov-05 6:31

What you are experiencing is windows' method of representing shortcuts. So what you have to do in order to get the text "p&m" is to use the folowing ampersand escape sequence:

DrawText(_T("p&&m"), LPRECT(CRect(0,0,100,100)), DT_LEFT);

For more details look up escape characters on msdn

Re: DrawText !!

hatemtaleb15-Nov-05 7:09

hatemtaleb

15-Nov-05 7:09

DrawText(_T("Thank you Mike && mikanu for your help"), LPRECT(CRect(0,0,100,100)), DT_LEFT | DT_NOPREFIX) Wink | ;)

VS6: Enabling breakpoints per thread

Chintoo72315-Nov-05 6:04

Chintoo723

15-Nov-05 6:04

In Visual Studio 6, is it possible to enable breakpoints only for a certain thread? It is little annoying when the debugging context suddenly changes to another thread.

If it is not possible in Visual Studio 6, is it possible atleast in WinDbg?

thanks!

Re: VS6: Enabling breakpoints per thread

David Crow15-Nov-05 7:22

David Crow

15-Nov-05 7:22

You can put conditions on breakpoints. If you have a variable that represents the active thread, you could use that.

"Take only what you need and leave the land as you found it." - Native American Proverb

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.