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I made an activex control in MFC. i created CButton on the control window. when i tested the control in VB, i found out the button doesn't function correctly for some reason: it doesn't respond to any message. As soon as i pointed my mouse to any other control on the VB form and come back to hit the button, it becomes alright.
any ideas?
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I had a OLD DLL built with Visual C++ 4.0 that has a method
ShowDialog (CString, CString*)
now when i rebuild my application in VC++ 6.0 which is using this dll then the compatibility problem arises and software crashes
restriction here is that I dont have source code for that old dll so i have to make my application (which is calling that old DLL) to call this function in such a way to get the same results as the previous one.
Note: DLL is modifying the second parameter of ShowDialog that is why its a pointer to CString
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This may just be the first sign of trouble.
You can't mix MFC versions, especially if the DLL is an AFX Extension DLL. But if it's not, you're still in trouble with functions that use MFC classes as parameters.
Your best bet would be get a copy of VC4, then wrap that DLL in a new DLL that exposes only POD types (Plain old data), such as char *, int, etc..
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The problem i encounter is: A thread is posting messages to the main application thread, and they get lost when a CFileDialog is open. I thought it was related to modal dialogs, but the problem does not exist with other types of modal dialogs. The messages do not appear neither in PreTranslateMessage nor in ProcessMessageFilter of the main application object.
if anyone has any idea of where to look for these messages, I would appreciate.
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MSVC++ has output toolbar wich has some tabs. One of those is Debug tab in which i can write using TRACE() macro. I would like to write data into some other tab which is not full of other data, like Result tab, but i cant find any data how to do it. Could anyone plz help me with this?
Thx for reading this, but i need some answers 
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There is no (documented) way that (I know of) a program running in it's own address space can write into any of the other tabs except the debug tab.
However, if you are writing an Add-In or a macro you can use the PrintToOutputWindow method of the Application interface and the text will go into a new tab called 'Output'.
HTH
Jignesh
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A newbie ponders on why he has to use pointers.  Also,
when to use it in exchange of simple object instantiations.
Clarifications please! TIA!
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I'll try a stab at the first part...
I've always thought its helpful to understand how the processor accesses memory in order to understand pointers.
Consider that a lot of what a cpu does consists in getting some value from memory into its registers, or copying some values from one place to another. Most instructions have a series of 'modes' depending on whether they will operate reg to reg, immediate to reg, or mem to reg etc.
For example:
mov cx,word ptr [ebx+6]
gets the two bytes at the memory address pointed to by 'the number in the ebx register plus 6', and moves it into the cx register.
Because the C language was designed to be 'close to the metal' it seemed like a good idea to allow for a construct that would mimic this kind of addessing. In C, the above assembly would be:
cx = *(ebx+6);
...er ... assuming a bit of setup to map the registers...
Anyway, you can easily extend this to more 'indirect' addressing where you get the value 'pointed at by the pointer at this address' etc. And you can write therewith some honking fast code.
HTH
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You ask questions that are better answered by a book on C programming. However, I will do my best to give you an accurate answer.
A pointer is simply a variable whose value is the address of another variable. In the C language they serve two main purposes:
1. To represent arrays. In C, and array is a pointer to a block of memory which holds the elements contiguously. In fact, strings in C are represented as arrays of characters.
2. To pass a function parameter by reference. Whenever a function needs to modify a parameter, it does so using pointer semantics. Here's an example:
void zero(int* pN)
{
*pN = 0;
}
void foo()
{
int n;
zero(&n);
}
Notice that n is not a pointer but its address can be assigned to a pointer variable, which is what pN is.
So, as you can see, pointers are a necessity in C whenever you need to use arrays or pass parameters by reference. In contrast, C++ has objects and reference types which can greatly reduce your need to use pointers.
Now, as far as when to use pointers instead of simple object instanciations? For that you need to understand that simple object instanciations (on the call stack) are great if you only need the object to live within the scope of the block where you created it. If it needs to stay around longer, then you need to use pointers. Here's what I mean:
void foo()
{
int n = 1;
int* pN = new int;
*pN = 1;
keep(pN);
keep(&n);
}
void keep(int* pItem)
{
}
So you see that this is a case where we need to hang on to the variable inside a container or something, then it needs to be allocated in the heap (with new) so it doesn't go away automatically like local variables do. The fact that we store the elements in the container by pointer also makes that very efficient in terms of speed and space. Pointers are only 4 bytes long (in Win32) and they can be copied as quickly as copying an integer. In contrast, if your container held its elements by value, it could take up more room and be less efficient to move elements in and out of it.
I hope I have shed some light to your pointer doubts. Again, it may help to complete the picture by picking up a good set of books on C/C++ programming.
Regards,
Alvaro
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Rather than a technical answer, I'll answer your question in a different way.
You can consider a pointer to be a reference (don't confuse this with C++ references). Now, suppose you were writing a paper on some subject and needed references to your data. What do you do? Usually you include a bibliography which merely gives information on how to find the actual data rather than listing the data itself (which could be quite volumous).
pointers work the same way. Rather than using the volumous data itself, you are simply using a reference to that data which "points" to the data.
This has some interesting side-effects which make programming easier. For instance, you can take a complex expression and refer to it simply by a pointer to that expression. example: char *p = this->that->somethingelse->whilestandingonyourhead->my_string.
Now you need only refer to p, rather than the long reference.
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http://www.codeproject.com/cpp/pointers.asp
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ummmm
so ... windows address book file format ... or more specifically ... how to read it short of loading it in as a binary file image and searching for likely looking email addresses
yah yah yah i know i posted this one before but no-one answered ... *sniff sniff*
mostly watching the human race is like watching dogs watch tv ... they see the pictures move but the meaning escapes them
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Hi,
How do we pass a structure from VC++/VB client to VC++ (DLL/ocx or
Automation) ?
how do we access the structure of VC++(DLL) from VC++ or VB client.
do let me know ASAP.
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shared memory
either a named pipe or a memory mapped file or a home grown mechanism
was that fast? i thought that was fast
mostly watching the human race is like watching dogs watch tv ... they see the pictures move but the meaning escapes them
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I'm trying to put an edit control on a CListCtrl subitem. Placing the edit control in a "cell" is fairly straightforward, but I have some rectangle calculation/position problems.
1) To make the sub-item "cells" taller, I added a 1-pixel wide bitmap that's a little taller than the font used by the dialog box. The listcontrol also uses grid lines. When I calculate the edit control's rectangle (based on the subitem rectagle size), it comes up in the correct position, but it's two pixels too high. Without the imagelist, it is positioned 2 pixes too low.
To make it even more strange, this only happens on my machine at home (win98, IE 4.01). At work (NT4/SP6a, IE 5.0), it comes up in exactly the right place.
2) When I use the image list to make the rows taller, the header control row doesn't vertically fill its row. Can I (and how do I) correct this condition?
3) Is there a "proper" way to make the rows taller without using an imagelist? The reason I ask is because the user may select a larger font (Windows display properties) than I'm expecting.
4)Is there a definitive reference for using list controls (MSDN is severely lacking in available info).
Thanks in advance.
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Check CListCtrl at www.codeguru.com. I used something once that came from there
Alberto Gattegno
Software Engineer
http://www.itginc.com
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regarding point 3 ... i also use an image of the size i want to make the line taller
point 1 ... are the system display properties the same on all machines?
point 2 ... hmmmmmmm
point 4 ... there was a posting to code project recently that gave a pretty thorough dusting to the listview ctrls and the headers
mostly watching the human race is like watching dogs watch tv ... they see the pictures move but the meaning escapes them
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please...
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I get an error message when trying to insert the Microsoft animate control, after inserting the avi res I insert the activex then plug in oninitdialog()
m_animate.Open( IDR_AVI1 );
m_animate.Play(0,-1,-1);
I've also tried m_animate.Open("myavi.avi");
to no avail
cannot convert parameter 1 from 'const int'
to 'const char *'
cannot convert parameter 1 from 'const int' to 'const struct tagVARIANT &'
from the CAnimation wrapper class...
void Open(LPCTSTR bstrFilename);
void Play(const VARIANT& varRepeatCount, const VARIANT& varStartFrame, const VARIANT& varEndFrame);
Can someone please help.
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Hi,
Try exactly this:
m_animate.Open("myavi.avi");
m_animate.Seek(0);
m_animate.Play(0,-1,-1);
Good Luck!
" I love water, but hate to drown! "
-- Masoud Samimi
Website: www.geocities.com/samimi73
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thanks for the response but errors out
'Seek' : is not a member of 'CAnimation'
listed in animate.h
// Operations
public:
void SetAutoPlay(BOOL bNewValue);
BOOL GetAutoPlay();
void SetBackStyle(long nNewValue);
long GetBackStyle();
void SetCenter(BOOL bNewValue);
BOOL GetCenter();
void SetEnabled(BOOL bNewValue);
BOOL GetEnabled();
long GetHWnd();
void SetBackColor(unsigned long newValue);
unsigned long GetBackColor();
long GetOLEDropMode();
void SetOLEDropMode(long nNewValue);
void Close();
void Open(LPCTSTR bstrFilename);
void Play(const VARIANT& varRepeatCount, const VARIANT& varStartFrame, const VARIANT& varEndFrame);
void Stop();
void OLEDrag();
};
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Hi,
Few questions first:
1- Are you using Appwizard to generate the starting code?
2- Are you putting the Animate Control from within the resource editor?
If all above are Yes, then see if you have the following lines in the stdafx.h file:
#ifndef _AFX_NO_AFXCMN_SUPPORT
#include <afxcmn.h>
#endif // _AFX_NO_AFXCMN_SUPPORT
If not, then copy and paste the above lines into the file and test compile again. Hope it solves it!
" I love water, but hate to drown! "
-- Masoud Samimi
Website: www.geocities.com/samimi73
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Thanks a million that worked. But I can't get the avi to play. I get an error messagem_animate.Play(0,-1,-1);
I've also tried m_animate.Play("0,-1,-1);
to no avail
cannot convert parameter 1 from 'const int' to 'const struct tagVARIANT &'
from the CAnimation wrapper class...
void Play(const VARIANT& varRepeatCount, const VARIANT& varStartFrame, const VARIANT& varEndFrame);
any suggestions?
thanks
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Hi,
Happy to know it worked! 
I'd like to suggest that either you post to me some of your code lines or if you'd like I post to you a very small sample app!
As I asked in my last reply, please explain how are you using the Animate Ctrl? Where are you getting it from. For example I always put it on a dialog created with resource editor, from the Controls toolbar!
Let's fix this thing!
Cheers
" I love water, but hate to drown! "
-- Masoud Samimi
Website: www.geocities.com/samimi73
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sorry about the non disclosure,
I'm putting it on a dialog created by right clicking on the dialog and "Inserting ActiveX control", and allowing the Microsoft Animate 6.0 control to add the wrapper class.
I'm emailing you the code so you can see the full project
Note it does not have the last changes you mentioned
thanks
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