Visual C++ File Processing: The Save and Open Dialogs

	File Processing: Using the Save and Open Dialogs

Introduction

The approach we used in our introduction to file processing is appropriate if you don't want the user to participate in saving or opening a file. In many applications, you will leave it up to the users to decide when and where to save a file or when and from where to open a file. This can be done by using the Windows common Dialog boxes designed for file processing.

When a user decides to save or open a file, you can use a CFileDialog variable and call the CFileDialog::GetFileName() method to get the name of the file that the user is dealing with.

Practical Learning: Introducing File Processing

If you want to follow this exercise, open the application created in our introduction and follow in the next section.
If you didn't create it, then create a new application using MFC AppWizard (exe) or MFC Application
Name it Palace Ice Cream
Change the design of the IDR_MAINFRAME icon as follows:

Design the dialog box as follows:

Control	ID	Caption	Additional Properties
Static Text		First Name:
Edit Box	IDC_FIRST_NAME
Static Text		Last Name:
Edit Box	IDC_LAST_NAME
Static Text		Address:
Edit Box	IDC_ADDRESS
Static Text		City:
Edit Box	IDC_CITY
Static Text		State:
Edit Box	IDC_STATE
Static Text		ZIP Code:
Edit Box	IDC_ZIP_CODE
Static Text		Hourly Salary:
Edit Box	IDC_HOURLY_SALARY
Group Box		Employment Status
Radio Button	IDC_PART_TIME	Part Time	Group: True Left Text: True
Radio Button	IDC_FULL_TIME	Full Time	Left Text: True
Button	IDOK
Button	IDCANCEL

Using either the ClassWizard or the Add Member Variable Wizard, add the following member variables to the controls:

Identifier	Value Variable
IDC_FIRST_NAME	CString	m_FirstName
IDC_LAST_NAME	CString	m_LastName
IDC_ADDRESS	CString	m_Address
IDC_CITY	CString	m_City
IDC_STATE	CString	m_State
IDC_ZIP_CODE	long	m_ZIPCode
IDC_HOURLY_SALARY	double	m_HourlySalary
IDC_PART_TIME	int	m_EmploymentStatus

Save everything

The Windows Save/Open Common Dialog Boxes

In our introduction, we managed to automatically save or open a file without little intervention from the user. If you want to let the user decide on these issues, you can use the File Dialog.

Practical Learning: Using the File Dialog Box

Add two new buttons to the bottom section of the dialog box as follows:

Control	ID	Caption
Button	IDC_SAVE_BTN	Save
Button	IDC_OPEN_BTN	Open
Button	IDC_RESET_BTN	Reset

Save all
Double-click the Save button and accept the suggested name of the file
Double-click the Open button and accept the suggested name of the file
Double-click the Reset button and accept the suggested name of the file

Implement both events as follows:

// Palace Ice CreamDlg.cpp : implementation file
//

#include "stdafx.h"
#include "Palace Ice Cream.h"
#include "Palace Ice CreamDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CPalaceIceCreamDlg dialog

CPalaceIceCreamDlg::CPalaceIceCreamDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CPalaceIceCreamDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CPalaceIceCreamDlg)
	m_FirstName = _T("");
	m_LastName = _T("");
	m_Address = _T("");
	m_City = _T("");
	m_State = _T("");
	m_ZIPCode = 0;
	m_HourlySalary = 0.0;
	m_EmploymentStatus = 0;
	//}}AFX_DATA_INIT
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CPalaceIceCreamDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CPalaceIceCreamDlg)
	DDX_Text(pDX, IDC_FIRST_NAME, m_FirstName);
	DDX_Text(pDX, IDC_LAST_NAME, m_LastName);
	DDX_Text(pDX, IDC_ADDRESS, m_Address);
	DDX_Text(pDX, IDC_CITY, m_City);
	DDX_Text(pDX, IDC_STATE, m_State);
	DDX_Text(pDX, IDC_ZIP_CODE, m_ZIPCode);
	DDX_Text(pDX, IDC_HOURLY_SALARY, m_HourlySalary);
	DDX_Radio(pDX, IDC_PART_TIME, m_EmploymentStatus);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CPalaceIceCreamDlg, CDialog)
	//{{AFX_MSG_MAP(CPalaceIceCreamDlg)
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_SAVE_BTN, OnSaveBtn)
	ON_BN_CLICKED(IDC_OPEN_BTN, OnOpenBtn)
	ON_BN_CLICKED(IDC_RESET_BTN, OnResetBtn)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CPalaceIceCreamDlg message handlers

. . .



void CPalaceIceCreamDlg::OnSaveBtn() 
{
	// TODO: Add your control notification handler code here
	this->UpdateData();

	CFile flEmployees;
	char strFilter[] = { "Employees Records (*.mpl)|*.mpl|Palace Ice Cream Files (*.pis)|*.pis|All Files (*.*)|*.*||" };

	CFileDialog FileDlg(FALSE, ".mpl", NULL, 0, strFilter);

	if( FileDlg.DoModal() == IDOK )
	{
		if( flEmployees.Open(FileDlg.GetFileName(), CFile::modeCreate | CFile::modeWrite) == FALSE )
			return;
		CArchive ar(&flEmployees, CArchive::store);

		ar << m_FirstName << m_LastName << m_Address << m_City << m_State << m_ZIPCode << m_HourlySalary << m_EmploymentStatus;
		ar.Close();
	}
	else
		return;

	flEmployees.Close();
}

void CPalaceIceCreamDlg::OnOpenBtn() 
{
	// TODO: Add your control notification handler code here
	CFile flEmployees;
	char strFilter[] = { "Employees Records (*.mpl)|*.mpl|Palace Ice Cream Files (*.pis)|*.pis|All Files (*.*)|*.*||" };

	CFileDialog FileDlg(TRUE, ".mpl", NULL, 0, strFilter);
	
	if( FileDlg.DoModal() == IDOK )
	{
		if( flEmployees.Open(FileDlg.GetFileName(), CFile::modeRead) == FALSE )
			return;
		CArchive ar(&flEmployees, CArchive::load);

		ar >> m_FirstName >> m_LastName >> m_Address >> m_City >> m_State >> m_ZIPCode >> m_HourlySalary >> m_EmploymentStatus;
		ar.Close();
	}
	else
		return;

	flEmployees.Close();

	UpdateData(FALSE);
}

void CPalaceIceCreamDlg::OnResetBtn() 
{
	// TODO: Add your control notification handler code here
	this->m_FirstName.Format("");
	this->m_LastName.Format("");
	this->m_Address.Format("");
	this->m_City.Format("");
	this->m_State.Format("");
	this->m_ZIPCode = 0;
	this->m_HourlySalary = 10.15;
	this->m_EmploymentStatus = 1;

	this->UpdateData(FALSE);
}

Test the application