C / C++ / MFC

problem with variable in 2 diferent dialog boxes

9-Nov-05 9:53

i have a open gl book but i dont see some marks how to display text on youre screen.
i think that you have to calculate them with vectors or somthing like that
but i'm realy not that far in that stuf i'm a beginer
i dit look fast troug the book i have on open gl
but i don't see a remark on how to put text on the screen

i hope that some other person wil find the trik

-- modified at 17:33 Wednesday 9th November, 2005

Saving exceptions

Federico Milano9-Nov-05 9:07

Federico Milano

9-Nov-05 9:07

Hi!

I'm coding a cache for Dynamic Object Loading. I'm using a third party library that throws some exceptions when it doesn't find the dynamic library that is requested. The thing is that I would like to store somewhere those exceptions and associate them to the object that the client was looking for. This way I could save a call to the third party library when I know that last time it failed: I would directly throw the exception that I saved the first time it failed (I also have a timer to clean up these associations and look for the library again...but that doesn't matter). The problem is that I don't know how to store in a container the exceptions, without risking to commit slicing and without hard coding the exceptions types of the third party library?

I would really appreciate any suggestion that you can give me.

Thanks,

Federico

Mathieu Dijkstra9-Nov-05 8:59

Re: problem with variable in 2 diferent dialog boxes

9-Nov-05 8:59

hi im new to windows programming and i am studiing the book in dutch
so sorry for my bad english.

problem is this:

i can't get data from dialog box 1 in to dialog box 2

kan anny one tel me wy this is
thank you verry much m.t. dijkstra
this is the litle program
www.palcopy.com/down_load/comunication_between_variabel_of_2_windows.zip
you can down load it frome my home page
the problem is in
m_waardeChild = a box in the 2th window where the text must be displayed

and
m_TestOutput = a input box in the 1th window where you come in !!!!

this is wat the second window must do

if in the second dialog is kliked on buton problem
then get input variabel frome 1 dialog en write it down in second window
but it dos not work????
void CChildDialog::OnBUTTONproblem()
{
// TODO: Add your control notification handler code here
// m_waardeChild = "this works";
// m_waardeChild = CComunicationbetweenvariabelof2windowsDlg.m_TestOutput;// dos not work
// m_waardeChild = CComunicationbetweenvariabelof2windowsDlg->m_TestOutput;// dos not work
m_waardeChild = CComunicationbetweenvariabelof2windowsDlg* m_TestOutput;

// can anny one tel me how this works in c++ i dont understand
// to get data from the other window up in here?????

UpdateData(FALSE);
}

thank's verry much for helping

-- modified at 15:35 Wednesday 9th November, 2005

David Crow9-Nov-05 10:11

Re: problem with variable in 2 diferent dialog boxes

9-Nov-05 10:11

Which of these two best describes the relationship between the two dialogs?

Are both dialogs owned by the same parent:

     parent
    /      \
dlg 1     dlg 2

Or does one dialog own the other:

parent
  |
dlg 1
  |
dlg 2

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

Mathieu Dijkstra9-Nov-05 10:24

Re: problem with variable in 2 diferent dialog boxes

9-Nov-05 10:24

parent
|
dlg 1

like this
in parent there is a variabel

in
dlg
there is a function who wil get the variabel frome the parent

void CChildDialog::OnBUTTONproblem()
{
geting data frome dlg1
}

how is this manegd

thank's verry much for helping

David Crow9-Nov-05 10:34

Re: problem with variable in 2 diferent dialog boxes

9-Nov-05 10:34

There are several ways to do this. The easiest, although not considered good OO practice, is to mark the variable as public in the parent class. Then in the child, simply call GetParent(). Or, mark the variable as private and use a get/set method instead.

Also, you could add the same type of variable to the child, mark it as public, and assign it a value before calling the dialog's DoModal() method.

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

Mathieu Dijkstra9-Nov-05 11:07

Re: problem with variable in 2 diferent dialog boxes

9-Nov-05 11:07

m_TestOutput is in main window and is public

this is standing in dialog 1 under buttonproblem

void CChildDialog::OnBUTTONproblem() <br />
{<br />
	CWnd *CParentWindow = GetParent();// Get pointer from parent window<br />
<br />
	m_waardeChild = CParentWindow->m_TestOutput;// dos not work ether<br />
//<br />
<br />
// can anny one tel me how this works in c++ i dont understand<br />
// to get data from the other window up in here?????	<br />
	<br />
	UpdateData(FALSE);	<br />
}

get folowing error
--------------------Configuration: comunication between variabel of 2 windows - Win32 Debug--------------------
Compiling...
ChildDialog.cpp
c:\sevc6\comunication between variabel of 2 windows\ChildDialog.cpp(54) : error C2039: 'm_TestOutput' : is not a member of 'CWnd'
c:\program files\microsoft visual studio\vc98\mfc\include\afxwin.h(1899) : see declaration of 'CWnd'
Error executing cl.exe.

comunication between variabel of 2 windows.exe - 1 error(s), 0 warning(s)

thank's verry much for helping

-- modified at 17:11 Wednesday 9th November, 2005

Mathieu Dijkstra9-Nov-05 22:57

Re: problem with variable in 2 diferent dialog boxes

9-Nov-05 22:57

can any one help me whit this problem im a beginer in this

thank's verry much for helping

David Crow10-Nov-05 2:36

Re: problem with variable in 2 diferent dialog boxes

10-Nov-05 2:36

Mathieu Dijkstra wrote:
UpdateData(FALSE);

My first suggestion would be to lose the calls to UpdateData(). They are unnecessary and will only confuse you further. Using SetWindowText() and GetWindowText() instead is much cleaner and less error-prone.

Mathieu Dijkstra wrote:
m_waardeChild = CParentWindow->m_TestOutput;// dos not work ether

The compiler is telling you exactly what the problem is. Try:

CComunicationbetweenvariabelof2windowsDlg *pParent;
pParent = (CComunicationbetweenvariabelof2windowsDlg *) GetParent();
m_waardeChild = pParent->m_TestOutput;

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

Mathieu Dijkstra10-Nov-05 7:17

Re: problem with variable in 2 diferent dialog boxes

10-Nov-05 7:17

wel i tryd it and it wont work this is wat i dit in the function
--------------------------------------------

void CChildDialog::OnBUTTONproblem() <br />
{<br />
<br />
	// TODO: Add your control notification handler code here<br />
<br />
<br />
	CComunicationbetweenvariabelof2windowsDlg *pParent;<br />
	pParent = (CComunicationbetweenvariabelof2windowsDlg *) GetParent();<br />
	m_waardeChild = pParent->m_TestOutput;<br />
<br />
<br />
<br />
// can anny one tel me how this works in c++ i dont understand<br />
// to get data from the other window up in here?????	<br />
	<br />
	UpdateData(FALSE);// to put data on screen (i wil change it in the future to	SetWindowText() must first look how it works i think somthing like this but not tested SetWindowText(m_waardeChild); // but as usual c++ wil say it's wrong<br />
}

-------------------------------------------------------------------------------
message by visual c++6 =
--------------------Configuration: comunication between variabel of 2 windows - Win32 Debug--------------------
Compiling...
ChildDialog.cpp
c:\sevc6\comunication between variabel of 2 windows\ChildDialog.cpp(60) : error C2065: 'CComunicationbetweenvariabelof2windowsDlg' : undeclared identifier
c:\sevc6\comunication between variabel of 2 windows\ChildDialog.cpp(60) : error C2065: 'pParent' : undeclared identifier
c:\sevc6\comunication between variabel of 2 windows\ChildDialog.cpp(60) : warning C4552: '*' : operator has no effect; expected operator with side-effect
c:\sevc6\comunication between variabel of 2 windows\ChildDialog.cpp(61) : error C2059: syntax error : ')'
c:\sevc6\comunication between variabel of 2 windows\ChildDialog.cpp(62) : error C2227: left of '->m_TestOutput' must point to class/struct/union
Error executing cl.exe.

comunication between variabel of 2 windows.exe - 4 error(s), 1 warning(s)
Frown | :(

thank's verry much for helping

David Crow10-Nov-05 8:20

Re: problem with variable in 2 diferent dialog boxes

10-Nov-05 8:20

Mathieu Dijkstra wrote:
c:\sevc6\comunication between variabel of 2 windows\ChildDialog.cpp(60) : error C2065: 'CComunicationbetweenvariabelof2windowsDlg' : undeclared identifier

Again, the compiler is telling you the problem. You have referenced an identifier that has not been declared. You need to include Comunicationbetweenvariabelof2windowsDlg.h at the top of ChildDialog.cpp.

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

Mathieu Dijkstra10-Nov-05 8:31

10-Nov-05 8:31

cool that was the problem
many thanks 4 helping me wit my study on variabels and multy dialogs
Smile | :)

problem is solved
i go studithis verry carful becorse i was having a problem whit this over 1 year
many thanks;)

waw you are a supper coder (by the way i had this problem also on a dutch formum but they dit not solve it) thanks agen

Fast files

hint_549-Nov-05 7:42

9-Nov-05 7:42

Hi there! I'm writting an app that deals a lot with files (both reading and writting) and that is slowing down my app.

What I need is a fast way to do the following operations on files:

- read
- writte
- append
- open
- close

I'm using c++ but inline assembly is an option.

Thx!

cgreathouse9-Nov-05 8:12

cgreathouse

9-Nov-05 8:12

What APIs are you using for File I/O? Have you done any profiling to see where the bottlenecks are?

Since File I/O is extremly slow compared to memory I/O, I don't think you'll see much difference between C++ and assembly. Without knowing more about you app, it's difficult to give any advice.

Chris

hint_549-Nov-05 9:06

9-Nov-05 9:06

I am writting a file compressing app.

But, for now, I'm just improving/optimizing the compressing algorithm that I'm using.

This algorithm as to writte a lot of bytes on several files (depending on the original file's size) and I'm using fwrite(), fopen(), fclose(), fseek() and fread() from stdio.h.

bottlenecks - I don't known what that is!

Is this helpfull? Thx!

cgreathouse9-Nov-05 9:36

cgreathouse

9-Nov-05 9:36

Bottlenecks are spots in your code where most of the execution time is spent. I would suggest you profile you app and see where most of the time is spent. If you're using VC6 there is a profile that ships with it. It takes some reading to figure out how to use it (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/_core_using_profile.2c_.prep.2c_.and_plist.asp[^])

There's also a way to run from VS but it doesn't always work(http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/_core_using_profile.2c_.prep.2c_.and_plist.asp[^])

If you're using VS 2002 or 2003 you'll have to get the profiler from compuware. They have a freebie version available (http://www.compuware.com/products/devpartner/profiler/default.asp?cid=3019X36&focus=DevPartner&source=Web+%2D+Evaluation+Request&desc=Download+%2D+%27DevPartner+Profiler+Community+Edition%27&offering=DevPartner&sf=1&p=0[^])

If you're using VS 2005 there is a profile included.

Once you see where most of the time is being spent you can then start to think about how to improve the performance.

hint_549-Nov-05 10:48

9-Nov-05 10:48

My app spends most of its time reading from/writing to files. This is the main reason why I need a fast way to read/write files as the rest of the algorithm isn’t much time consuming, I’d say 85% of the time spent in the compressing algorithm is with files.

I need a fast way to read/write files in sequence.

thx.

hint_54

David Crow9-Nov-05 9:55

9-Nov-05 9:55

hint_54 wrote:
bottlenecks - I don't known what that is!

It is a metaphor for trying to cram a bunch of work into a small passage. With a bottle, no matter its capacity, there is a physical limit to the amount of liquid that can pass through the neck (which is usually narrower than the bottle itself).

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

David Crow9-Nov-05 8:34

9-Nov-05 8:34

A memory-mapped file might save you a small amount of time.

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

hint_549-Nov-05 9:15

9-Nov-05 9:15

hhhmmm... You are talking about DMA rigth? I don't know how to use it with files!

Thx!

[Message Deleted]

Mathieu Dijkstra9-Nov-05 9:31

9-Nov-05 9:31

[Message Deleted]

David Crow9-Nov-05 9:49

9-Nov-05 9:49

hint_54 wrote:
You are talking about DMA rigth?

No. DMA is a way to access memory independently of the CPU.

hint_54 wrote:
I don't know how to use it with files!

A memory-mapped file is a spot in memory that can be accessed (e.g., open, close, read, write, seek) as though it were an actual file. By eliminating file I/O, a speed increase is (normally) realized. See these for examples:

http://www.ecst.csuchico.edu/~beej/guide/ipc/mmap.html

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

http://www.codeproject.com/file/xreverse.asp

http://www.codeproject.com/file/findidaddressbook.asp

http://www.codeproject.com/file/Memory_Mapped_Class___PBD.asp

http://www.codeproject.com/win32/cmemmap.asp

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

hint_549-Nov-05 10:06

9-Nov-05 10:06

Yes, I know what you mean but isn’t that memory consuming for larger files?

hint_54

David Crow9-Nov-05 10:17