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Thanks for the reply. I would like you to clarify a couple of points though.
Alvaro Mendez wrote:
extern int nTest; extern void foo();
In that case, the linker uses the ones defined globally in A.cpp.
To finish my point, by making the variable and function "static", the linker ties them to the files themselves and does not treat them as globals.
If all variables and functions that are not declared as "static" are automatically treated as global, then what is the purpose of "extern"? I was under the impression that extern was necessary for the value of a variable or function to persist across multiple source files. Is this true or no? And, how and when is "extern" used? If I wanted a variable or function to persist across multiple source files, would I just declare and define it in one of the source files and then put "extern <datatype> <variable name="">" in one of the common header files included at the top of each source files? Or is "extern" unnecessary in that case?
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Remember that everything in C must be declared. If you want to use a variable defined in another file, you need to declare it in yours as extern. That's what extern is for: to tell the current file that you're using a variable defined somewhere else. If you don't use the extern keyword, the compiler thinks that you're defining it in that file.
Note that the extern keyword is only necessary for global variables. Functions don't really need it since the compiler can tell that you're not defining them by the fact it's a prototype with no body.
So, to sum it up, the extern keyword is necessary for a variable (not just its value) to be made visible across multile files.
Regards,
Alvaro
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What's the easiest way to build an application with the look and feel of an MMC? I don't need any snap-ins. I need the look and feel plus the treeview on the left hand side and listview on the right hand side.
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I have created a project a while back.. anyway, I selected not to have active x objects in my project.. now a few weeks later I decided that I need to put an active x object into my dialog project.. but when I put the object into the project the dialog box will no longer appear when its launched.. any ideas?
If I remove the object the dialog box will appear.. its a Microsoft web browser active x object.
Thanks
Rob
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Or The activex is not registered or you forgot to add AfxOleInit() in the InitInstance of your project....
Best Regards
Carlos Antollini.
Sonork ID 100.10529 cantollini
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Hi, veterans, how can I delete a character in CRichEditView?
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First you need to use CRichEditCtrl::SetSel and select the text or character that you need to delete, then CRichEditCtrl::ReplaceSel replazing your selection for "" and ready
Best Regards!!
Carlos Antollini.
Sonork ID 100.10529 cantollini
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Thanks, Carl, this is great.
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i have a dialog that looks like this:
+-------------+
| +---------+ |
| | A | |
| +---------+ |
| |
| +---------+ |
| | B | |
| +---------+ |
+-------------+
A and B are static frames that may hold other controls.
i want to be able to dynamically resize it so that it is either just big enough to hold the "A" rectangle or big enough to hold both A and B. to keep it easy, the width never changes.
so, what's the secret to getting the height correct? i'm doing this:
CRect dispRect;
m_dispBox.GetWindowRect(dispRect);
ScreenToClient(dispRect);
dispRect.NormalizeRect();
CRect normalRect;
m_normalFrame.GetWindowRect(normalRect);
ScreenToClient(normalRect);
normalRect.NormalizeRect();
int w = normalRect.left + normalRect.Width() + GetSystemMetrics(SM_CXDLGFRAME) * 2;
int h = normalRect.top + normalRect.Height() + GetSystemMetrics(SM_CYDLGFRAME) * 2;
if (bShow)
{
h += dispRect.Height();
h += (dispRect.top - normalRect.bottom);
}
SetWindowPos(&wndTop, 0,0, w, h, SWP_NOMOVE | SWP_NOZORDER);
but the dialog is just a little bit too small to hold the bottom frame. - the bottom frame's bottom is clipped.
-c
Smaller Animals Software, Inc.
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I prefer to use GetWindowPlacement and SetWindowPlacement when I work with resize of controls...
Best Regards
Carlos Antollini.
Sonork ID 100.10529 cantollini
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With GetClientRect() you get the dimension of the client rect.
I prefer to use GetWindowPlacemente because it has the rcNormalPosition member in the WINDOWPLACEMENT struct, when I change the size of each control I use SetWindowPlacement..... Try this
Carlos Antollini.
Sonork ID 100.10529 cantollini
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Hi all, I have a small crappy problem. When I load a bitmap I retrieve its width and height, and I want to make the screen view the exact same size. However, I also want to prevent the frame being resized over this size, and so I have managed to implement a system which takes care of it. However, all of the code is situated in the Child Frame class, where the maximum tracking sizes are specified. I then go on to use SetWindowRect(). The problem I get though, is that when using SetWindowRect() the whole width of the window AND frame is set the bitmap dimensions, which means part of the bitmap is obsured by the frame. I have implemented my own offset (to account for the frame), and it works on my computer (or any other with a 19inch monitor), the trouble is I have to demo my app on the computers in Uni, and their monitors are 15inches (and I run XP, they run win2k which means the border sizes are different too), which means the frame will be out of sync with the image (I have tested this). Anyway, how could I get it to set the window and view to the right size? Can I obtain a border offset value? or is there a better way of achieving what I want?
Cheers all,
Alan.
"When I left you I was but the learner, now I am the Master" - Darth Vader
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Try adjust the rectangle using "AdjustWindowRectEx".
Normski. - Professional Windows Programmer
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Took me a while to get it going, but it worked an absolute treat, thank you for the response Norm.
Much Appreciated,
Alan.
"When I left you I was but the learner, now I am the Master" - Darth Vader
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Hello,
I am looking for a listCtrl with editable items and checkBoxes.
Anyone know where I can find it?
Where there is a WISH, there is a WILL.
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Use the extended Styles for List Contorls.
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For editable items, handle LVN_BEGINLABELEDIT. For checks, set the LVS_EX_CHECKBOXES extended list style.
--Mike--
http://home.inreach.com/mdunn/
Help! Help! I'm being repressed!!
your with and
Sonork - 100.10414 AcidHelm
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When we are extracting data with serialize( ar >> some_variable >> another_one >> etc. ) is it possible to 'rewind' and begin again, for instance, if we don´t find a desired value?
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Yes. But you should destruct the file's CArchive before rewinding the CFile, and create a new CArchive after rewinding. This will ensure the archive's data integrity.
"There is always one more bug..."
ravib@ravib.com
http://www.ravib.com
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Thanks.
So, how could I do it in this small sample code:
void CMeteoGraficaDoc::Serialize(CArchive& ar)
{
CDocument::Serialize(ar);
if (ar.IsStoring())
{
ar<<datosF.dia<<datosF.mes;
}
else
{
ar>>datosF.dia>>datosF.mes;
// if (datosF.dia != some_value) ...... rewind and begin to serialize.
}
}
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Hmmm, I must have been brain dead when I posted my earlier reply. You can rewind the file during serialization.
void CMeteoGraficaDoc::Serialize(CArchive& ar)
{
CDocument::Serialize(ar);
if (ar.IsStoring()) {
ar<<datosF.dia<<datosF.mes;
}
else {
ar >> datosF.dia>>datosF.mes;
if (datosF.dia != some_value) {
CFile* pFile = ar.GetFile();
ASSERT (pFile != NULL);
pFile->SeekToBegin();
ar >> datosF.dia>>datosF.mes;
}
}
} /ravi
"There is always one more bug..."
http://www.ravib.com
ravib@ravib.com
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Ok, thank you so much
I´ll try it.
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