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I am building an ActiveX control using MFC.
I wonder how can I update the property window when I change a property of type IUnknown from the property page?
I did the following but it is not working with IUnknown property:
In the DoDataExchange of the property page I called a function that sets a new value for the property as follows:
In the property page file:
void CMyPropertyPage::DoDataExchange(CDataExchange* pDX)
{
// NOTE: ClassWizard will add DDP, DDX, and DDV calls here
// DO NOT EDIT what you see in these blocks of generated code !
//{{AFX_DATA_MAP(CPowerListPpgData)
.
.
//}}AFX_DATA_MAP
DDP_PostProcessing(pDX);
if (pDX->m_bSaveAndValidate)
SaveValue();
}
BOOL CMyPropertyPage::SaveValue(IUnknown* lpPropValue, LPCTSTR lpstrPropName)
{
USES_CONVERSION;
COleDispatchDriver PropDispDriver;
ULONG ulObjects;
LPDISPATCH *ppDisp = GetObjectArray(&ulObjects);
DISPID dwDispID;
LPCOLESTR lpOleStr = T2COLE(lpstrPropName);
for(ULONG i = 0; i < ulObjects; i++)
{
if(SUCCEEDED(ppDisp[i]->GetIDsOfNames(IID_NULL, (LPOLESTR*)&lpOleStr, 1, 0, &dwDispID)))
{
PropDispDriver.AttachDispatch(ppDisp[i], FALSE);
PropDispDriver.SetProperty(dwDispID, VT_UNKNOWN, lpPropValue);
PropDispDriver.DetachDispatch();
}
else
return FALSE;
}
return TRUE;
}
In the CTL file:
void CMyCtrl::SetMyProperty(LPUNKNOWN newValue)
{
.
BoundPropertyChanged(dispidMyProperty);
SetModifiedFlag();
}
Is there special case for the proeprties of type IUnknown?
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Hello, Sir:
Maybe i want to catch some exception where my program? Has somebody a class of catching and managing exception? Can you help me?
Thanks in advance.
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HansonDavid wrote:
Maybe i want to catch some exception where my program? Has somebody a class of catching and managing exception?
C++ has exception handling in the language. eg.
try
{
...
}
catch( some_exception e )
{
}
and Windows has Structured Exception Handling - SEH. There are a number of good articles here on CP on Exception handling which should help you get started.
Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com
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Thanks Sir. Maybe I want a class of catching and managing exception. Because i am working a program . The programe need some FPU instruction. I am afraid of these FPU instrucrions generating some exception error. And i want to catch these exception and manage these exception. I think jusut a class maybe is better.
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what do you want to do ?
maybe have a look at "wizard" type dialogs sequence ...
Maximilien Lincourt
"Never underestimate the bandwidth of a station wagon filled with backup tapes." ("Computer Networks" by Andrew S Tannenbaum )
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is there any way other than using CPropertyPages and CPropertySheets?
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Property sheets and pages are a good solution. Alternatively you can create another dialog every time the previous one exits (ugly), or you create one dialog and move the controls around dynamically depending on the events (not very reusable).
Lorenz Prem
Microsoft Corporation
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Hello all,
As a beginner in MFC/Visual C++, I'm trying to write a very simple text editor in order to learn things. I am using the SDI framework which associates a frame window, a view and a document. The code is very short and simple, and is nearly identical to the MULTIPAD sample found in VC++, except that it's using SDI instead of MDI.
When I type text in the window, it gets displayed correctly, but when I try to open a file, all I get on my screen are strange | characters and not the content of the file.
I've traced the program execution CEditView::SerializeRaw() (my CDocument derived class calls SerializeRaw() in its Serialize() method) to see what could be wrong. I've found that the file gets read properly, and looking at the buffer's content in CEditView::ReadFromArchive(), all is OK at this point. This suggests that something goes wrong after the call to CEditView::GetEditCtrl()::SetHandle(). Since SetHandle() is implemented using messages, I don't know how to debug this further.
I'm having a hard time figuring out what is possibly wrong with this code, and any help would be greatly appreciated. 
Thanks,
Maxime
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Hello all,
As a beginner in MFC/Visual C++, I'm trying to write a very simple text editor in order to learn things. I am using the SDI framework which associates a frame window, a view and a document. The code is very short and simple, and is nearly identical to the MULTIPAD sample found in VC++, except that it's using SDI instead of MDI.
When I type text in the window, it gets displayed correctly, but when I try to open a file, all I get on my screen are strange | characters and not the content of the file.
I've traced the program execution CEditView::SerializeRaw() (my CDocument derived class calls SerializeRaw() in its Serialize() method) to see what could be wrong. I've found that the file gets read properly, and looking at the buffer's content in CEditView::ReadFromArchive(), all is OK at this point. This suggests that something goes wrong after the call to CEditView::GetEditCtrl()::SetHandle(). Since SetHandle() is implemented using messages, I don't know how to debug this further.
I'm having a hard time figuring out what is possibly wrong with this code, and any help would be greatly appreciated.
Thanks,
Maxime
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Hi there,
i wrote a ocx in MFC which has no user interface (hust empty rectangle is
display on the client form).
However, PreTranslateMessage is never called.
How can i solve that problem?
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It's not your problem.
Container implementation should call IOleInPlaceActiveObject::TranslateAccelerator method when properly implemented.
Regards
"...Ability to type is not enough to become a Programmer. Unless you type in VB. But then again you have to type really fast..."
Me
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Igor,
thanks for the reply.
However, i don't understand what you wrote.
Let me explain what i need:
I want to build an MFC OCX that uses TWAIN to scan images from flatbed scanner.
There is already microsoft ocx for that, named ImgScan.ocx. However, it is not good for me, because i don't know how the get the image from it if it configured not to be saved to file.
In order to work with the TWAIN i have to give it my window handle and i need to have a message loop.
Everything works fine when i work with the TWAIN in a SDI application where I overrided the PreTranslateMessage.
However PreTranslateMessage is never called in the OCX.
My OCX has no user interface, i mean it has no controls.
Do you know how to get messages in PreTranslateMessage in the OCX?
How do i get the window handle of my OCX?
I tried something else: creating a hidden window. But stil the PreTranslateMessage is never called .
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I was saying that in standard implementation of OleControl it's responsibility of container to call IOleInPlaceActiveObject::TranslateAccelerator method of current InPlaceActiveObject on each keyboard/mouse message before processing it inside of container.
Because you are using MFC and probably derived your control from COleControl: Correct implementation of IOleInPlaceActiveObject::TranslateAccelerator inside of your control should call PreTranslate message of your COleControl derived class: you may serach for the code in MFC for COleControl::XOleInPlaceActiveObject::TranslateAccelerator implementation (file CTLINPLC.CPP).
Now, from what you explained: your control is not standard COleControl and it has it's own messagepump --> it makes it more complicated -- but in that case I'll be looking into just calling PreTranslateMessage in your message loop.
Regards,
I
"...Ability to type is not enough to become a Programmer. Unless you type in VB. But then again you have to type really fast..."
Me
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Igor,
I have created a thread which own its window message queue and
it seems wo work fine.
Nevertheless, I will try what you have suggested.
Thanks,
Dudi
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Hello,
I'm trying to create an interface (in CView) with solid shapes that are custom CWnd derived controls - I want a result much like the shapes that you can add and manipulate in powerpoint, word etc. However I'm having bother with Z-Order. I can rearrange the Z-Order using SetWindowPos() but:
If a shape(CWnd) gets put at the bottom of the Z-order it obscures windows that are above it (at the top) of the z-order.
If I put a shape(CWnd)at the top of the z-order it receives mouse-clicks but is obscured by shapes below it in the Z-order.
What I want is for a shape that is at the top of the Z-order to be drawn so it obscures those below it AND accepts the mouse click - just as happens in Powerpoint, Word etc.
Perhaps I am missing something about this Z-order business 'cos it doesn't seem logical to me!?
Any help would be greatly appreciated
AGBIRT
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ummmmmmm
dunno about making the shapes separate windows
i would maintain a list of shapes and z-orders for the current view and draw them correctly (painters algorithm) in the OnPaint() handler
"there is no spoon"
biz stuff about me
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Hi!
I created a dialog with a button. When I press that button the thread is started (it opens a dialog with progress bar and abort button - it's basically to show the progress of some lenghty operation that can be aborted (something like Copy in Total Commander).
The code works fine in Debug mode, but it doesn't work in Release mode (you have to set: Property Pages for project->C/C++->Optimization->Optimization to Disabled (/0d), so that it works.
Can anyone explain me why is that?
Here is a code I wrote:
//header of CthreadprogressdlgDlg
afx_msg void OnBnClickedButton1();
LRESULT EndWorkDlg(WPARAM, LPARAM);
CWorkDlg dlg; //the dialog with progress bar and abort button
//implementation
BEGIN_MESSAGE_MAP(CthreadprogressdlgDlg, CDialog)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
//}}AFX_MSG_MAP
ON_BN_CLICKED(IDC_BUTTON1, OnBnClickedButton1)
ON_MESSAGE(WORK_END_DLG, EndWorkDlg) //THIS
END_MESSAGE_MAP()
void CthreadprogressdlgDlg::OnBnClickedButton1()
{
dlg.DoModal();
}
LRESULT CthreadprogressdlgDlg::EndWorkDlg(WPARAM, LPARAM)
{
dlg.EndDialog(IDOK);
return 0;
}
//WorkDlg header
afx_msg void OnBnClickedOk();
bool work;
static UINT Go( LPVOID pParam );
//WorkDlg implementation
BOOL CWorkDlg::OnInitDialog()
{
CDialog::OnInitDialog();
AfxBeginThread(Go, static_cast<LPVOID>(this), THREAD_PRIORITY_NORMAL); //this
return TRUE; // return TRUE unless you set the focus to a control
// EXCEPTION: OCX Property Pages should return FALSE
}
void CWorkDlg::OnBnClickedOk()
{
work = false;
}
UINT CWorkDlg::Go( LPVOID pParam )
{
CWorkDlg *pD = static_cast<CWorkDlg*>(pParam);
while(pD->work) //some long long operation (and the progress bar shows how long it is)
{
}
pD->GetParent()->SendMessage(WORK_END_DLG);
pD->work = true; //reset, so that it will run the next time.
return 0;
}
Does maybe anyone know a better way to do this?
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When you say it works fine, how do you know? You haven't included the CWorkDlg class, but I assume Go() isn't a static function, in which case it can't be used as a thread function. But your biggest problem is worker threads don't have access to the CWnd* objects in the handle map of the main thread. So pD->GetParent()->SendMessage(WORK_END_DLG); is unlikely to work. Also using SendMessage() from a worker thread to the main app thread is not a good idea at all as you can get into deadlock situations.
I suggest you do lots of reading on multithreading as it is a difficult and complex area which is fraught with problems for the unitiated. You'll find articles here on CP which will help.
Oh and when you post code use the pre, code format toolbar options and the 'Do not treat <'s as HTML tags' or <> buttons which all make your code a lot more readable.
Neville Franks, Author of ED for Windows. Free Trial at <a href="http://www.getsoft.com">www.getsoft.com</a>
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I agree 100%... And yes avoid SendMessage() bewcause of problems with deadlock situations. The GUI can cause a deadlock that has nothing to do with your events or mutexes...
John
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I've made some modifications to the program:
work thread in CWorkDlg doesn't send message anymore, it just says dlg->EndDialog(IDOK) (it works fine too)
I didn't find any memory leaks or something like that. It exits fine. Everything works ok.
It's not that of a complex thing:
One dialog (the main one) is for gathering data. When all data is gathered you start the long calculations -> Another dialog is created (dialog with progress bar and abort button). When the calculation finishes the dialog closes or you can abort it and it's closed then. That's it. Any ideas how to do that?
The problem is here (like I described before):
The code works fine in Debug mode, but it doesn't work in Release mode (you have to set: Property Pages for project->C/C++->Optimization->Optimization to Disabled (/0d), so that it works.
And another abnormality I found:
If I leave Optimization on speed (default for release) and I add some code into the while(pD->work) loop, then it also exits fine.
I would be very grateful if someone could help.
I'd like to send a project somewhere so that you all that are willing to help could see.
Where can I do that?
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I'm afraid you are totally kidding yourself if you think whatever problems you are seeing have something to do with Debug vs. Release Build. It is just dumb luck that it is working in a Debug build. Apologies if this sounds harsh, but multithreading is really quite difficult to do and unless it is done properly you and your users will have nothing but problems.
You can't use any CWnd* derived objects in your worker thread, so dlg->EndDialog(IDOK) is no better than SendMessage(). The only safe way to work with another threads Windows is to *only* use HWND's to access them, and only ever use PostMessage(). All you say is "doesn't work" which is quite useless really.
Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com
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One solution is PostMessage(). Another solution is SendNotifyMessage().
Kuphryn
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#include <afxwin.h>
class cwinmain : public CFrameWnd
{
public:
cwinmain();
DECLARE_MESSAGE_MAP()
};
cwinmain::cwinmain()
{
Create(NULL, "Title");
}
class capp : public CWinApp
{
public:
BOOL InitInstance();
};
BOOL capp::InitInstance()
{
m_pMainWnd=new cmainwin;
m_pMainWnd->ShowWindow(m_nCmdShow);
m_pMainWnd->UpdateWindow();
return true;
}
BEGIN_MESSAGE_MAP(cmainwin,CFrameWnd)
END_MESSAGE_MAP()
capp app;
==========================
whenever i tried to compile above code in vc++ 6 compiled sucessfully
but it shows 4 error while linking so what r the likely problem
plz help me i m new to this world
..@>
/( )\
^ ^
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What errors did you get?
Ryan "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"
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