C / C++ / MFC

Aseem Sharma wrote:

tell me the best book

Trupti Mehta wrote:

David, not to use UpdateData, then what to use?

Trupti Mehta wrote:

On above code in UpdateData, I get "ASsertionFailure" File dlgdata.cpp: line 52 error, I choose Retry/Ignore

Trupti Mehta wrote:

On coming of Child 2, I get "Out Of Memory" Error.

Jijo raj wrote:

Could you get me the call stack? Press "retry" and it will take you to debugger. Just press "Alt+7" and you can see the Call stack window.

void DataEntryDialog::CreateChildDialogs()   // CALLED IN OnInitDialog()....
{
	CRect rect(4, 2, 5,2);

	childPage1.CRHCreateGenericChildDialog(this, &rect,IDD_PAGE1_DLG, NULL);
	childPage1.SetDeptStock(deptStock);
	childPage1.ShowWindow(SW_SHOW);

	childVisible = 1;
	free(rect);

	return;
}

CPage1Dlg::~CPage1Dlg() {
	m_operName.Empty();       // CString
	deptStock.~DeptStock();   // Object
//	operatorsMap->RemoveAll();   // CMap
	delete operatorsMap;      // CMap*

//	this->DestroyWindow();
}

void CPage1Dlg::TellParent()
{
//	AfxMessageBox(_T("Inside TellPArent"));

	// Update deptStock obj with the parent
	this->CRHPostMessageToParent(WM_CHANGED_DS, (int)&deptStock);
	this->ShowWindow(SW_HIDE);
	this->CRHPostMessageToParent(WM_SHOW_NEXT_VIEW, 2);
//	AfxMessageBox(_T("Finished TellParent"));

	return;
}

afx_msg LRESULT DataEntryDialog::OnSHOW_NEXT_VIEW(WPARAM wparam, LPARAM lparam) {
	
//	AfxMessageBox(_T("Going to sHOW Page 2 "));

	int childView = (int)lparam;
	
	DestroyVisibleChild();

	CRect rect(4, 2, 5,2);

	switch(childView) {
		case 1:
			childPage1.CRHCreateGenericChildDialog(this, &rect,IDD_PAGE1_DLG, NULL);
			childPage1.SetDeptStock(deptStock);
			childPage1.SetOperatorsMap(operMap);
			childPage1.ShowWindow(SW_SHOW);
			break;
		case 2:
			// Page 2
			AfxMessageBox(_T("ABOUT Create Child 2"));
			childPage2.CRHCreateGenericChildDialog(this, &rect, IDD_PAGE2_DLG, NULL);
			childPage2.SetDeptStock(deptStock);
			childPage2.ShowWindow(SW_SHOW);
			AfxMessageBox(_T("Shown"));
			break;
		case 3:
			childPage3.CRHCreateGenericChildDialog(this, &rect, IDD_PAGE3_DLG, NULL);
			childPage3.SetDeptStock(deptStock);
			childPage3.SetDepartmentsMap(deptsMap);
			childPage3.ShowWindow(SW_SHOW);
			break;
	}

	childVisible = childView;
	free(rect);

	return 0;
}

void DataEntryDialog::DestroyVisibleChild()
{
	CString s;
	s.Format(_T("Destroying %d child"), childVisible);
	AfxMessageBox(s, MB_SETFOREGROUND);
	s.Empty();
	switch(childVisible) {
	case 1:
		childPage1.~CPage1Dlg();	// Destructor calls DestroyWindow()
		childPage1.DestroyWindow();
		AfxMessageBox(_T("Destroyed Child 1"));
		break;
	case 2:
		childPage2.~CPage2Dlg();	// Destructor calls DestroyWindow()
		break;
..........

Trupti Mehta wrote:

i have a practise of calling just dd.~DeptDetails(), but someone pointed out, "Calling destructor without freeing the memory", so where am I going wrong. And keeping that in mind, in many such places I have called free(&dd) before the destructor.

Trupti Mehta wrote:

t present I pass object via parent & update the parent back by CHANGED_DS message. Is their any better way to work out which might reduce sending msg to parent for updated object.

Jijo raj wrote:

I can see a chance of serious synchronization error. Your UpdateData() is called after sending notification to the parent? In that case, your child dialog will get deleted by parent dialog and after deletion you might be calling UpdateData() which will endup in assertion from MFC. Its a wild guess, since i don't have the full picture of your code.

void CPage1Dlg::OnGetData()
{
	AfxMessageBox(_T("Into OnGetData"));
	UpdateData(true);

	// Search operator no
	OperatorDetails od;
//	if (operatorsMap->Lookup(m_number, od) != 0) {	// Found operator number
//		m_operName = od.GetOperName();

	if (true) {
		m_operName = "Trial";
		UpdateData (false);
		AfxMessageBox(m_operName);
		EnableConfirm(true);
	} else {
		m_operName = "";
		EnableConfirm(false);
	}

	od.~OperatorDetails();
	UpdateData (true);

	return;	
}
// Enables /Disables the Confirm Y/N? & Yes,No buttons
void CPage1Dlg::EnableConfirm(bool enable)
{
	if (enable) {
		GetDlgItem(IDC_NAME_BTN)->ShowWindow(false);
		GetDlgItem(IDC_CONFIRM_LABEL)->ShowWindow(true);
		GetDlgItem(IDC_YES1_BTN)->ShowWindow(true);
		GetDlgItem(IDC_WRONG_BTN)->ShowWindow(true);
	} else {
		GetDlgItem(IDC_NAME_BTN)->ShowWindow(true);
		GetDlgItem(IDC_CONFIRM_LABEL)->ShowWindow(false);
		GetDlgItem(IDC_YES1_BTN)->ShowWindow(false);
		GetDlgItem(IDC_WRONG_BTN)->ShowWindow(false);
	}
}

void CPage1Dlg::OnYes()
{
	// Create object of OperatorDetails with provided info
	OperatorDetails* odet(m_number, m_operName);
	// Update the DeptStock
	deptStock.SetOperator(odet);
	// Free up the memory of OpertatorDetails
	free(&odet);
	odet.~OperatorDetails();

	// Communicate with the Parent
	TellParent();

	return;
}
void CPage1Dlg::TellParent()
{
//	AfxMessageBox(_T("Inside TellPArent"));

	// Update deptStock obj with the parent
	this->CRHPostMessageToParent(WM_CHANGED_DS, (int)&deptStock);
	this->ShowWindow(SW_HIDE);
	this->CRHPostMessageToParent(WM_SHOW_NEXT_VIEW, 2);
//	AfxMessageBox(_T("Finished TellParent"));

	return;
}