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Justin, I posted your code on a BBS I read, and someone responded that it gives the expected output using gcc. So chalk it up to a VC bug, I guess.
Something else that's weird - if you try to set breakpoints on the A() and B() constructors, it will only let you break at one of them. VC will say there's no code at the line the other constructor is on. *shrug*
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Justin, I found this MS KB article that acknowledges that this is a bug in VC. The workaround is to throw a dummy template parameter in the function, i.e.:
template<typename T> void func ( T* dummy = NULL )
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Is anyone familiar with programming the Rich Ink control for a WinCE 2.11 device? If not, do you have any suggestions for implementing signature capture. Thanks.
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I am trying to move a combo box to a new location when a specific event happens. The code I currently have is:
CComboBox* state;
// box is initialized, blah blah blah
// then, later I have
state->MoveWindow(x, y, WIDTH_INC, HEIGHT_INC, TRUE);
This causes the following error:
The instruction "0x5f436c36" referenced memory at "0xcdcdcded". The memory could not be "read".
Using the debugger to step through the program, I've discovered in the MoveWindow function, it asserts at
ASSERT(::IsWindow(m_hWnd))
Any ideas what's happening?
Thanks,
Stephanie
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Probably you called the MoveWindow function too early. I.e. before the controls are actually created.
If I recall correctly, they are created before/after the CDialog::OnInitDialog event.
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Here's the sequence:
The user fills in some edit fields and pushes an Allocate button. The CComboBox is created and displayed.
Everything is good at this point. I can select different items from the drop down box and everything. If
the user has selected the Allocate button more than once, there could be several of the CComboBoxes.
When the user selects a Deallocate button, the CComboBox is removed the remaining boxes need to be
moved up (they're displayed vertically). This is when MoveWindow gets called and crashes.
Does this makes sense? The CComboBox has definately been created because I can select items from it.
Do you have any other suggestions?
Thanks,
Stephanie
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Sounds like you may be goiong in a loop somewhere to move other boxes up, so don't you think you might be trying to move the one that is already gone, possibly?
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I thought of that also, so I put in
if (state)
AfxMessageBox("Box is good");
else
AfxMessageBox("Box is bad");
I got the Box is good message, so I think the box is still there. Is this an accurate test to see if the box
exists? Any other ideas?
Thanks again,
Stephanie
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Hi Stephanie,
Testing a pointer to a MFC object is not enough, it could be not associated to a Windows object anymore.
To see if the combobox exists, you should call ::IsWindow() just like the debug assertion.
I think you have to believe that 
Maybe, a code snippet that shows how you destroy the control and then reference it could be more helpful.
I also think you are using the deleted object at some point.
Cheers,
Paolo
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No one noticed the value of the pointer! 0xCDCDCDED screams "uninitialized data". When a stack variable is allocated, it's filled with 0xCD so you can see that the variable hasn't been initialized yet. So Stephanie, wherever your MoveWindow() call is, you're calling it through an uninitialized pointer.
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Actually, I had noticed that, especially since I had just encountered a CWnd pointer like that in my program and I put in special logic to test for 0xcdcdcdcd. I was being methodical about the problem so that is why I started out by asking what is "state"? Your answer is also good, since it seems that your answer did not require a reply. I do not know what I was thinking, but I guess I needed more information before I could help. Perhaps I just got distracted by confusion about the rest of the question and forgot to mention about the 0xcdcdcdcd stuff, so it is good you caught it.
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That's exactly the problem. I discovered it last week, but didn't post it. (I guess I should have.)
Thanks for your help.
Stephanie
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Hi,
I've a problem in handling the Event Sink of a activeX control, which is created dynamically in the code.
I created a MDI application, in that on the MDIFramewnd's Oncreate function I created a 3'rd party ActiveX control with it's parent as the MDIFrameWnd. To handle the ActiveX events i created the Event Sink macro's
manually. But it seems that it is not calling the events in my MainFrame implementation. How can add a event handler for the activeX control. Please help me.
Advance thanx,
Subbi.
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I 'm programming about connect Outlook 2000 by vc++ and i will
get value from outlook (Meeting or calendar) and write to file and then
i will import file to outlook . Now i meet some problem about time this it
set. When i get meeting of 15 June 2000 from outlook 2000 and write to file,
and then i import by read this file to outlook i have new nneting but this time of
meeting it 's not 15 June 2000 , but it is time now .
I worry about it very much
Please who have used or programming with file name msoutl9.cpp please tell me
or it have new file that 's not msoutl9.cpp Plese tell me .
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Is it possible to use the word spell checker from a Visual C++ programm. Any samples?
thank's
Tom
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Im working on a little program that does on command drawing
eventually plotting / cutting (Very lucky to have opportunity to experiment on high tech peice of machinary  ) )I had a program thatused a CArray<cpoint,cpoint> collection but I need to have another two variables in a adition to a point. I tried using a class which had all neccissary variables and then tried to use it in a simar type collection but this didnt work.
How should I go about this??? CObArray??
I need to be able to 'add'Items and then read items sequentially.
thanks for the time
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You can create separate instances of the class using new.
Then add the pointer to that class data to the CObArray.
Just remember to create a function to properly delete items prior to emptying the array, or else you will discover that you have memory leaks.
I usually use a for loop to fetch each item's pointer, delete the items via the pointer, then erase all the pointers by calling RemoveAll on the array when I am done with the data.
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See: http://home.socal.rr.com/samhobbs/VC/Collections.html
The CObList sample can probably be used as an exmple of a CObArray also, with the obvious variations.
I think, however, that a CArray would be good too and might be easier. If you used it as in:
CArray <cfieldsrecord, cfieldsrecord&=""> m_FieldsRecords;
then it would store and retrieve your class items and you could delete everything with a simple:
m_FieldsRecords.RemoveAll();
when you are through. So what was the problem with CArray? I have used them and they work well and are easy to use. I think it would be worthwhile to determine what the problem is and solve it.
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Well In fact I did solve the problem with the CArray and again Im sorry for the poorly written post I was a little
mindboggled last night!!!
I have a class whose constructor is as follows
JPoint(CPoint CP, int state, int Ptool);
This is the object I needed an array of..
In a SetCoordinates function I had code similar to this:
FixedMap.Add(JPoint((100,100),0,1));
Still a newbee I assumed that (100,100) would be assumed to be the CPoint required by the JPoint constructor;
And the fact I recieved no compiler errors lead me to beleive it should work. But when it came draw the points in another function nothing was displayed...
The problem was not prefixing (100,100) with CPoint as follows
FixedMap.Add(JPoint(CPoint(100,100),0,1));
Shouldve known better right???
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Can anyone tell me how to start a thread from inside a class's member function? I keep getting this error
C2664: '_beginthread' : cannot convert parameter 1 from 'void (void *)' to 'void (__cdecl *)(void *)'
None of the functions with this name in scope match the target type
Is this because I'm compiling it as a DLL? The _beginthread call looks like this:
_beginthread(WindowThread, 0, NULL);
and WindowThread is defined as:
friend void WindowThread(PVOID pvoid);
What am I doing wrong? I declared WindowThread as a friend inside the class definition, and I also tried it as a global function outside of the class. I'm stuck.
Thanks for any help given,
- J Woltman
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You should use _beginthreadex instead.
In class you define these:
// used for _beginthreadex
static DWORD WINAPI WriterStartThread(LPVOID);
// thread function which handles messages
virtual DWORD WriterThread(void);
// set when the thread has started running
HANDLE m_WriterThreadEvent; // write thread start event
// handle to the play thread
HANDLE m_WriterThreadHandle; // write thread handle
// thread identifier of play thread
DWORD m_WriterThreadID; // write thread identifier
This is in class function that starts the thread...
// start thread
m_WriterThreadHandle = (HANDLE)_beginthreadex(
(void *)((LPSECURITY_ATTRIBUTES)m_SecurityInfo),
0, // normal stack size
(PFBTEX)WriterStartThread,
(LPVOID)this, // pointer to this class
0, // instance data not used with callback threads
(unsigned *)&m_WriterThreadID
);
This is static member function that just acts to hand off call to the class virtual function.
It maps from the static domain into the class domain so that all thread processing can actually get to member variables.
// static
DWORD WINAPI MWCWaveFileWriter::WriterStartThread(
LPVOID lpData
){
// run member function
DWORD dwRetVal = ((PMWCWaveFileWriter)lpData)->WriterThread();
return( dwRetVal );
}
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When I looked up the documentation, I found that my error was with the using of __stdcall instead of __cdecl function calls. Is there I way I can explicitly tell it to use __cdecl for just the thread function? (I know that is probably a basic question, but I don't know how)
Thanks for the reply,
- J Woltman
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