I want to send a message from my child window (CDialog) to the parent window (CFormview). If I press the cancel button at the child window, the Dialog should quit and the program should continue with the code of the STOP-Button at the parent Window.
void ChildDialog::OnBnClickedCancel()
{
CDTParentView *pButtonWnd = (CDTParentView *)AfxGetMainWnd();
pButtonWnd->OnBnClickedbuttonStop();
CDialogEx::OnCancel();
}
but there is an error in this objore.cpp:
BOOL CObject::IsKindOf(const CRuntimeClass* pClass) const
{
ENSURE(this != NULL);
// it better be in valid memory, at least for CObject size
ASSERT(AfxIsValidAddress(this, sizeof(CObject)));
// simple SI case
CRuntimeClass* pClassThis = GetRuntimeClass(); <------- error
ENSURE(pClassThis);
return pClassThis->IsDerivedFrom(pClass);
}
Can anyone tell me, whats the problem?
And maybe post a better idea to send the button-clicked message?
Your code isn't actually sending a message, it's trying to call the handler directly. It's easy to simulate the clicking of a button the same way Windows would do it, then your existing code will handle it naturally.
CWnd * pMain = AfxGetMainWnd();
CWnd * pButton = pMain->GetDlgItem(ID_STOP_BUTTON);
pMain->PostMessage(WM_COMMAND, MAKEWPARAM(ID_STOP_BUTTON, BN_CLICKED), (LPARAM)pButton->m_hWnd);
AfxGetMainWnd does not return a pointer to the CFormView, it returns a pointer to the CMainFrame. If your dialog is modal you can simply check the return value of the DoModal call that displays the dialog. Or you might have better luck with calling GetParent to get a pointer to the CFormView.
Related
I have a dialog in which after pressing button OK, the program uses the data in the dialog and draws a plot. I need to draw the plot without having to close the dialog as with IDOK, hence the apply button.
The code with drawing the dialog is,
INT_PTR val = dlg->DoModal();
if ( val == IDOK) {
//draw plot
}
The code of onOK and onApply
void DLg::OnOK() {
GetDataGrid();
CDialog::OnOK();
}
void DLg::OnBnClickedApply()
{
GetDataGrid();
}
How do I get DoModal() to return a value on onApply() without closing the dialog?
Any help would be appreciated.
A modal dialog can't return a value and leave the dialog open. You could either make your dialog non-modal, or post your main window a message from the OnBnClickedApply function that makes it draw the plot.
I tend to put drawing into a separate thread and would call it wherever needed. So you can either
(1) call the OnDrawPlot again in your Apply button
if ( val == IDOK) {
AfxBeginThread(...);//draw plot
}
void DLg::OnBnClickedApply()
{
AfxBeginThread(...);//draw plot
}
(2) send the return value back to the DoModal using EndDialog method
What parameters are there in EndDialog ?
An example can be found here.
Declare a variable in CDialog derived class preferably public. Then just at OnOK assign this variable to appropriate value. The caller would use it directly.
class Dlg : public CDialog
{
public:
int TheVariable;
...
};
Call site:
if(dlg.DoModal()==IDOK)
{
dlg.TheVariable; // Use the variable
}
However, if you need to draw on the dialog itself (and not to other window, which has launched the dialog), then don't call CDialog::OnOK or EndDialog in your OnOK override. In this case, you need to do painting in dialog itself.
How do I disable MFC dialog OK button?
This code:
CWnd* fieldOK = pDlg->GetDlgItem(IDOK);
fieldOK->EnableWindow(FALSE);
causes exception "Access violation reading location..."
in line ASSERT(::IsWindow(m_hWnd) || (m_pCtrlSite != NULL)); of function CWnd::EnableWindow(BOOL bEnable) in winnocc.cpp from mfc90d.dll
In this time focus is on another control.
What's can be wrong?
Thanks for help.
[EDITED]
bool CSCalcNormCell::OnSelectionChanged( CWnd* pDlg, int type, int page, UINT ctrl_id )
{
DDX_DataBox(pDX.get(), IDC_WORKSHOP_COMBO, ws_code);
if (!CInfactoryPriceAdapter::CanEditPricesForWorkshop( ws_code ))
{
CWnd* fieldOK = pDlg->GetDlgItem(IDOK);
fieldOK->EnableWindow(FALSE);
}
else
{
CWnd* fieldOK = pDlg->GetDlgItem(IDOK);
fieldOK->EnableWindow(TRUE);
}
}
I'm not sure why would wouldn't be able to do it. If I take a regular CDialog and I do an init like this:
BOOL CMyDialog::OnInitDialog() {
CDialog::OnInitDialog();
CWnd *okbtn = GetDlgItem( IDOK );
if ( okbtn ) {
okbtn->EnableWindow( FALSE );
}
return TRUE;
}
it disables the button just fine. Perhaps something else is wrong?
Try this: http://support.microsoft.com/kb/122489
How to Disable Default Pushbutton Handling for MFC Dialog
Although default button (pushbutton) support is recommended, you might
want to disable or modify the standard implementation in certain
situations. You can do this in an MFC application by following these
steps:
Load the dialog into App Studio and change the OK button identifier
from IDOK to something else such as IDC_MYOK. Also, clear the check
from Default Button property.
Use ClassWizard to create a message
handling function for this button named OnClickedMyOK. This function
will be executed when a BN_CLICKED message is received from this
button.
In the code for OnClickedMyOK, call the base class version of
the OnOK function. Here is an example:
void CMyDialog::OnClickedMyOK()
{
CDialog::OnOK();
}
Override OnOK for your dialog, and do nothing inside the function. Here is an example:
void CMyDialog::OnOK()
{
}
Run the program and bring up the dialog. Give focus to a control other
than the OK button. Press the RETURN key. Notice that CDialog::OnOK()
is never executed.
I suspect the problem comes from pDlg pointer. When you call pDlg->GetDlgItem(IDOK), is the dialog already created already?
Make a breakpoint at the line CWnd* fieldOK = pDlg->GetDlgItem(IDOK); and debug into it to see if fieldOK pointer is null or a valid pointer.
That is why I think mark's answer is very close. You can disable it onOnInitDialog` or other members of you dialog class after it showed up.
The problem you have is that the button control has not been created on the interface yet. We do not get the full vision of your problem.
Anyway, you should protect your code from crashing. It is better that your code does nothing than to crash the application. Restructuring it like this avoids the access violation problem due to the NULL pointer:
bool CSCalcNormCell::OnSelectionChanged( CWnd* pDlg, int type, int page, UINT ctrl_id )
{
DDX_DataBox(pDX.get(), IDC_WORKSHOP_COMBO, ws_code);
CWnd* fieldOK = pDlg->GetDlgItem(IDOK);
if (fieldOK)
{
if (!CInfactoryPriceAdapter::CanEditPricesForWorkshop( ws_code ))
fieldOK->EnableWindow(FALSE);
else
fieldOK->EnableWindow(TRUE);
}
}
You need to load a bitmap for the disable mode of the OK button in LoadBitmaps() function.
Using pseudo funcs for subclassing:
CreateSpecialHandle(TWinControl *Control, const TCreateParams &Params, const AnsiString SubClass)
{
......;
set Control DefWndProc to SubClass.lpfnWndProc
set Control WindowHandle from CreateWindowEx
......;
subclass(TWinControl *Control);
}
subclass(TWinControl *Control)
{
......;
oldWProc = (void*)GetWindowLong(Control->Handle, GWL_WNDPROC);
oldDefWProc = (void*)(Control->DefWndProc);
oldWindowProc = Control->WindowProc;
MakeObjectInstance(newWProc) for SetWindowLong
MakeObjectInstance(newDefWProc) for Control->DefWndProc
Control->WindowProc = newWindowProc;
......;
}
Now, we have unexpected behavior of subclassed control.
WM_NCHITTEST result 0, etc...
For example when newWProc intercepts WM_NCHITTEST and sets Result to HTCLIENT
we have mouse response, but, is that not responding without setting msg.result to 1 for msg.msg WM_NCHITTEST consequence of my mistake and wrong subclassing, what else we need to handle manually?
newWProc make callback of oldWProc
newDefWProc make callback of oldDefWProc
newWindowProc calls oldWindowProc
Do we have to subclass parent control of subclassed control as well?
Also, sending WM_GETTEXT results with empty buffer.
Obviously, we are doing something wrong here. We need explanation,
Thank You all in advance
Update:
in TDCEdit:public TCustomEdit overriding CreateWindowHandle
void __fastcal CreateWindowHandle(const TCreateParams &Params)
{
CreateSpecialHandle(this,Params,TEXT("EDIT"));
}
void CreateSpecialHandle(TWinControl *Control,const TCreateParams &Params, AnsiString SubClass)
{
...
Control->WindowHandle = CreateWindowEx(...,"EDIT",....);
....
subclass(Control);
}
subclass(TWinControl* Control)
{
......;
oldWProc = (void*)GetWindowLong(Control->Handle, GWL_WNDPROC);
oldDefWProc = (void*)(Control->DefWndProc);
oldWindowProc = Control->WindowProc;
MakeObjectInstance(newWProc) for SetWindowLong
MakeObjectInstance(newDefWProc) for Control->DefWndProc
Control->WindowProc = newWindowProc;
......;
}
Now, when I use TDCEdit and intercept Message.Msg == WM_NCHITTEST
inside newWProc Message.Result is 0 and stay 0 through all message process chain.
Note that subclassing TCustomEdit is one among other controls we need to subclass
in project and we try to use same subclass(TWinControl*) function for all.
Here is part of newWProc with few more lines to focus on problem
void __fastcall TControlWrapper::newWProc(Messages::TMessage &Message)
{
if(Message.Msg == WM_NCHITTEST ) // TEST
if(Message.Result == 0)
Message.Result=1;//<- WHY I NEED TO DO THIS
if( Message.Msg == WM_DESTROY) {
HandleWMDestroy(Message);
return;
}
CallWindowProcW( (int(__stdcall*)())oldWProc,
Handle, Message.Msg, Message.WParam,
Message.LParam);
if(Message.Msg == WM_NCHITTEST )
if(Message.Result == 0)Message.Result=1;//<- OR THIS
}
This is a confusing question - it doesn't help that your code samples are not C++.
set Control DefWndProc to SubClass.lpfnWndProc
is not a line in a C++ function, for example. Can you show your actual code please?
I can make a guess at what you're trying to do: are you trying to subclass a window (perhaps a form?) so that it moves when the mouse is clicked on it? If so, you don't need to do any raw Windows API-style subclassing, the way you appear to be doing with GetWindowLong. In C++ Builder, the VCL is an object-oriented wrapper around the Windows API, and you can do this in one of two much cleaner ways:
Create a new WindowProc and set it; this is a property pointing to a new window procedure, and you simply call the old one too;
Create a descendant class of your TWinControl (if you're using a form, you already have one) and implement the virtual method WndProc.
An example of #1, in Delphi (but you should be easily able to convert it to C++) is in the Embarcadero documentation on subclassing WndProc.
An example of #2, the cleanest OO version, is here, and this actually shows how to do what you're trying to do, too: C++Builder: Create a TForm with BorderStyle bsNone that is nevertheless movable and resizable
Given what you appear to want to do, I would suggest going with #2.
In my SDI application i need to get this behawiour. After I click on a button on the FormView, a CDialog opens. When I press the OK button on the CDialog, I call a function of the FormView. I don't want to close the CDialog. I try to do it with modeless dialog, but when i call formview function from dialog, i can't access to formview's control, like it's lost hwnd; the error is can't read memory of m_hwnd, the hwnd is ???.
This is my code:
Open modeless dialog:
CCampiDlg *m_pDialog = NULL;
HWND hCampi = NULL;
// Invoking the Dialog
m_pDialog = new CCampiDlg;
if (m_pDialog != NULL)
{
BOOL ret = m_pDialog->Create(m_pDialog->IDD, this);
if (!ret) //Create failed.
{
AfxMessageBox(_T("Error creating Dialog"));
}
m_pDialog->ShowWindow(SW_SHOW);
}
when i press the ok button in the dialog i do:
CEditorTxView pView;
box2 = (CEdit*)(GetDlgItem(IDC_CAMPI_BOX2));
box2->GetWindowTextW(campo);
pView.inserisciCampo(1, campo);
In inserisciCampo function in CEditorTxView (CFormView) i have to do operation with my control txtCtrl, but it's lost hwnd. The declaration of txtCtrl is in the CEditorTxView.h
CTx1 txtCtrl;
And initialize it in DoDataExchange function:
void CEditorTxView::DoDataExchange(CDataExchange* pDX)
{
CFormView::DoDataExchange(pDX);
DDX_Control(pDX, IDC_TX1, txtCtrl);
}
Someone can help me plz?
I can give you two answers here:
How to do what you are asking (get access to a control of the CFormView from a modeless dialog)
How to solve your underlying problem (communicate changes in a modeless dialog to the owner view)
For the first one, you have to declare a pointer to the view in the dialog class and initialize it in the constructor of the view:
class CCampiDlg : public CDialog
{
public:
CCampiDlg(CEditorTxView* pView, CWnd*pParent = NULL) // Change declaration to add pointer to view
: m_pView(pView)
{
}
// ... Whatever
private:
CEditorTxView* m_pView;
}
Now in your button handler:
CEdit* box2 = (CEdit*)(GetDlgItem(IDC_CAMPI_BOX2)); // Why not use a control variable?
box2->GetWindowTextW(campo);
m_pView->inserisciCampo(1, campo);
This should do what you are asking for. However, it is the wrong way to do it.
The problem with this approach is that the dialog knows way too much about its parent. It knows it is of type CEditorTxView and that it has a member called inserisciCampo, that takes a number and some text.
It shouldn't know that much. In fact, knowing anything about it, other than it is of type CView or even CWnd, is too much.
If the dialog knows about the view, you can't reuse the dialog with other views, and anytime the view changes its representation (what now is a textbox may be a combobox in the future, for example) the dialog must change accordingly.
The solution would be to send a message to the parent, explaining what's happened. Then the parent (the view) should know haw to handle that event. For example:
class CCampiDlg : public CDialog
{
public:
CCampiDlg(CWnd*pParent = NULL) {}
protected:
OnOk()
{
CString campo;
c_CampiBox2.GetWindowText(campo);
GetParent()->SendMessage(UWM_CAMPO2_SET, 0, (LPARAM)&campo);
}
}
In the view:
// It can be ON_REGISTERED_MESSAGE:
ON_MESSAGE(UWM_CAMPO2_SET, OnCampo2Set)
//...
LRESULT CEditorTxView::OnCampo2Set(WPARAM, LPARAM lParam)
{
CString* s = (CString*) lParam;
inserisciCampo(1, *campo);
return 0;
}
Now, you have decoupled the view and the dialog. The dialog knows nothing about the view. You can change its type, change the representation, even make it a dialog, and you don't have to change anything in the dialog. And if you need that same modeless dialog somewhere else, you just drop it there, create a message handler in the parent, and voilà!
For further explanations and better examples, check these articles:
Dialog and control design (Your case is explained in the section "Notifications to the environment")
Message management
On Ok button click the below code is running:
CEditorTxView pView;
box2 = (CEdit*)(GetDlgItem(IDC_CAMPI_BOX2));
box2->GetWindowTextW(campo);
pView.inserisciCampo(1, campo);
Note that, you are creating the new pView in stack and it does't attach with any window. You are not actually referring the view that already created and launched your dialog acting a parent. Revisit the above code and try the get the view:
Try the below code, if it is not working (Google it)
CFrameWnd * pFrame = (CFrameWnd *)(AfxGetApp()->m_pMainWnd);
CView * pView = pFrame->GetActiveView();
I want to use Setwindowpos() in global function to change the postiion of one dialog.
So i coded like below
CWnd *pWnd = (CWnd*)pMain->GetDlgItem(IDD_TOOLBAR_DIALOG);//GetActiveFrame ();
pWnd->SetWindowPos(&CWnd::wndBottom,0,80,45,900,SWP_SHOWWINDOW);
pWnd returns as undefined value.
So i follow this method
CToolTab * tab;
tab = new CToolTab();
if(tab->GetSafeHwnd() == 0)
{
tab = new CToolTab();
if( tab->m_hWnd != NULL )
{
tab->SetWindowPos(&CWnd::wndBottom,0,80,45,900,SWP_SHOWWINDOW); }
}
But m_hWnd returns 0x0000.So in both cases SetWindowPos shows assertion error.
How can i get the handle of dialog in Global function?
Ok so i was thinking this through - and then it occurred to me that IDD_TOOLBAR_DIALOG is almost certainly the resource id for the dialog itself not a control on the dialog. You can't call GetDlgItem referencing the Dialog resource ID and expect to find the window that contains it (It simply won't work and you'll get back a null CWnd* pointer).
What is it that pMain points to? The main application window? Is that the parent to the Dialog?
Where in the code do you create the Dialog that want to move? At that point you must have a valid CWnd derived object for it? One solution would be to hold on to that as member variable to allow you call SetWindowPos on it later when necessary.