Windows Systems Programming: Spring 2002

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AppWizard at work
(build skeletal MFC application)

Using the App Wizard to Create the Infrastructure

Easiest way to generate a MFC application is to use VC++ Application Wizard

Select "File", "New" Project
Select MFC AppWizard (exe) and name it "Skeleton"/ OK
Select Single Document/unselect "Document/View architecture support"/Next
None (for database)/take defaults/Next
None (for compound document support)/turn off active X controls/Next
Turn off all options/Finish/OK
Try it out! source code

Now it is instructive to look at what you get for free.

Source Files:

ChildView.cpp: the "main" window for the application
MainFrm.cpp: parent of ChildView, may also contain status and toolbars, hence might be larger than the "main" childview window
Skeleton.cpp: the application object
StdAfx.cpp: for pre-compiled headers (optimization for preprocessing of macros, templates, etc - mostly used for MFC headers)
Skeleton.rc: stuff created/edited by the resource editor (menus, simple dialog, string table) - interesting to open as text

Header Files: for the above

Skeleton.h

#if !defined(AFX_SKELETON_H__BA3C1EA4_4590_11D1_A985_00609752BFB9__INCLUDED_)
#define AFX_SKELETON_H__BA3C1EA4_4590_11D1_A985_00609752BFB9__INCLUDED_

#include "resource.h"       // main symbols

class CSkeletonApp : public CWinApp
{
public:
	CSkeletonApp();

// Overrides
	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CSkeletonApp) 
	public:
	virtual BOOL InitInstance();
	//}}AFX_VIRTUAL

// Implementation

	//{{AFX_MSG(CSkeletonApp) 
	afx_msg void OnAppAbout();
		// NOTE - the ClassWizard will add and remove member functions here.
		//    DO NOT EDIT what you see in these blocks of generated code !
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};


/////////////////////////////////////////////////////////////////////////////

//{{AFX_INSERT_LOCATION}} 
// Microsoft Developer Studio will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_SKELETON_H__BA3C1EA4_4590_11D1_A985_00609752BFB9__INCLUDED_)

FOOTNOTES

FS1: Structured Comment used by the Class Wizard to stick new member functions, etc into this class

CSkeletonApp

BEGIN_MESSAGE_MAP(CSkeletonApp, CWinApp) 
	//{{AFX_MSG_MAP(CSkeletonApp)
	ON_COMMAND(ID_APP_ABOUT, OnAppAbout)
		// NOTE - the ClassWizard will add and remove mapping macros here.
		//    DO NOT EDIT what you see in these blocks of generated code!
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

// The one and only CSkeletonApp object

CSkeletonApp theApp;

/////////////////////////////////////////////////////////////////////////////
// CSkeletonApp initialization

BOOL CSkeletonApp::InitInstance()
{
	// Change the registry key under which our settings are stored.
	// You should modify this string to be something appropriate
	// such as the name of your company or organization.
	SetRegistryKey(_T("Local AppWizard-Generated Applications")); 

	// To create the main window, this code creates a new frame window
	// object and then sets it as the application's main window object.

	CMainFrame* pFrame = new CMainFrame;
	m_pMainWnd = pFrame;

	// create and load the frame with its resources

	pFrame->LoadFrame(IDR_MAINFRAME,
		WS_OVERLAPPEDWINDOW | FWS_ADDTOTITLE, NULL,
		NULL);

	// The one and only window has been initialized, so show and update it.
	pFrame->ShowWindow(SW_SHOW);
	pFrame->UpdateWindow();

	return TRUE;
}

FOOTNOTES

F1: Application has MessageMap
F2: Causes application settings to be stored in the registry. This function sets m_pszRegistryKey, which is then used by the GetProfileInt, GetProfileString, WriteProfileInt, and WriteProfileString member functions of CWinApp. If this function has been called, the list of most recently-used (MRU) files is also stored in the registry. The registry key is usually the name of a company. It is stored in a key of the following form: HKEY_CURRENT_USER\Software\<company name>\<application name>\<section name>\<value name>.
The _T is a macro which can convert to UNICODE if needed.
F9: Base class provides this - calls open file dialog, this is why there is such a uniform feel to file opening.

View Object

Instead of FrameWnd directly to allow for status and toolbars

Shows Data
Handles User Input Events

ChildView.h

class CChildView : public CWnd
{
// Construction
public:
	CChildView();

// Attributes
public:

// Operations
public:

// Overrides
	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CChildView)
	protected:
	virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
	//}}AFX_VIRTUAL

// Implementation
public:
	virtual ~CChildView();

	// Generated message map functions
protected:
	//{{AFX_MSG(CChildView)
	afx_msg void OnPaint();
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};


BOOL CChildView::PreCreateWindow(CREATESTRUCT& cs) 
{
	if (!CWnd::PreCreateWindow(cs)) // let base set up window structure
		return FALSE;

	cs.dwExStyle |= WS_EX_CLIENTEDGE; // then we can modify
	cs.style &= ~WS_BORDER;
	cs.lpszClass = AfxRegisterWndClass(CS_HREDRAW|CS_VREDRAW|CS_DBLCLKS,  
		::LoadCursor(NULL, IDC_ARROW), HBRUSH(COLOR_WINDOW+1), NULL);

	return TRUE;
}

void CChildView::OnPaint() 
{
	CPaintDC dc(this); // device context for painting
	
	// TODO: Add your message handler code here
	
	// Do not call CWnd::OnPaint() for painting messages
}

F3: likeSDK style of registering the window

FrameWindow Object

Top level window for the application.
but covered by child view (unless there is a status/tool bars
Handles "setFocus" and command messages - by passing them to the view or to the base class

// CMainFrame message handlers
void CMainFrame::OnSetFocus(CWnd* pOldWnd)
{
	// forward focus to the view window
	m_wndView.SetFocus(); // needed because it is the view that must handle user input
}

BOOL CMainFrame::OnCmdMsg(UINT nID, int nCode, void* pExtra, AFX_CMDHANDLERINFO* pHandlerInfo)
{
	// let the view have first crack at the command
	if (m_wndView.OnCmdMsg(nID, nCode, pExtra, pHandlerInfo)) 
		return TRUE;

	// otherwise, do default handling
	return CFrameWnd::OnCmdMsg(nID, nCode, pExtra, pHandlerInfo);
}

F4 another message routing structure for non-user generated messages
we will see more later - can be used to handle menu update messages

Resource File

Select "File/Open"
In file dialog, select "Skeleton.rc", select "text" in the "open as" list on the bottom/select "Open" button (if says already open, continuing will close the resource editor/ select "OK")

Part of this file defines the default menus

/////////////////////////////////////////////////////////////////////////////
//
// Menu
//

IDR_MAINFRAME MENU PRELOAD DISCARDABLE 
BEGIN
	POPUP "&File"
	BEGIN
		MENUITEM "E&xit",                       ID_APP_EXIT
	END
	POPUP "&Edit"
	BEGIN
		MENUITEM "&Undo\tCtrl+Z",               ID_EDIT_UNDO
		MENUITEM SEPARATOR
		MENUITEM "Cu&t\tCtrl+X",                ID_EDIT_CUT
		MENUITEM "&Copy\tCtrl+C",               ID_EDIT_COPY
		MENUITEM "&Paste\tCtrl+V",              ID_EDIT_PASTE
	END
	POPUP "&Help"
	BEGIN
		MENUITEM "&About Skeleton...",          ID_APP_ABOUT
	END
END

F5: the ampersand ('&') denotes a single character select
tab ('\t') Ctrl+Z is commentary on shortcut key which is set elsewhere
ID_EDIT_UNDO is identifier of command message sent by selecting this menu item (someone will need to write a message handler for it). In this case the only menu message handler you can easily see is that for the ID_APP_ABOUT

Toplevel menu includes "File", "Edit" and "Help"
Each top level item has a pop up menu with the indicated menu items

Other items of interest in this file are the shortcut key "accelerators" and the string table (which contains the "help" information associated with menu items.

You could edit this file to change the menu - or you could use the resource editor (since you opened this as text - close it, then select the "ResourceView" Tab.