Building an MFC Application
Using the Wizard
Terms
• Solution
–
–
–
–
–
–
–
–
A container for related projects
An executable or DLL
May be constructed from multiple projects
Each project or solution is a directory and its contents
May have different versions
May generate multiple applications
Solutions & projects manageable in W. Explorer
Logical relationship of solution:components does not
necessarily mirror the way they are stored on disk.
Solutions, Projects & directories
• Solution1 (in VS explorer view)
– App1 (Project 1)
• X.cpp
• X.h
– App2 (Project 2)
– App3 (Project 3)
• Visual Studio Projects (WinExplorer view)
– Solution 1 (folder)
•
•
•
•
•
App1 (folder)
App2 (folder)
App3 (folder)
Solution1.sln
Solution1.suo
(shareable metadata)
(user-specific metadata)
• App1 might depend on App2 & App3
– Managed with project dependencies
Project
• A container for items e.g.; code, .rc files
• May be used in other projects
• Types specify language,etc.
Using VS 2013 Premiere - 1
•
•
•
•
•
Open VS
Select FilenewProject
Select Visual C++
In the center area, select MFC Application
At the bottom of the screen, enter a name for
your project (like "JSmith-MFC-app")
– (use your own name!!)
– At the bottom right corner
• Check the box for "create directory"
• Click OK
Using VS 2013 Premiere - 2
• In the navigation panel, right-click your project name
(NOT the solution name)
• Click on Properties
• Ensure these values are present:
– Under General:
• Configuration type: Application (.exe)
• Use of MFC: Use MFC in a Shared DLL
– Assumes user's PC has MFC installed
– Faster than "Use MFC in a static library"
• Common language runtime (CLR): no CLR
– Under C/C++, Code Generation, Runtime Library
"Multithreaded Debug"
– Under Pre-compiled headers: "Not using pre-compiled
headers"
Using VS 2013 Premiere - 3
• You should now have
– Two .h files
• MainFrame.h – function prototypes & global variables
• MyWinApp.h – name of your program & project
#include <afxwin.h>
class CMyWinApp : public CWinApp
{public:
virtual BOOL InitInstance();
};
– Three .cpp files
• Main.cpp
#include "MyWinApp.h"
CMyWinApp MyApplication;
• MyWinApp.cpp – #include MyWinApp.h, InitInstance code
• MainFrame.cpp – #include both .h files, everything else
Classes & Global variables
• Declare global vars in MainFrm.h
• Define, initialize in PreCreateWindow or in OnCreate
------------ following is in MainFrm.h ---------------------class CMainFrame : public CFrameWnd
{ // no initializations here!!!
private: // declare global variables here
public: // declare constructors and prototypes for
// other functions in MainFrame.cpp
void OnPaint(); // for example
}
Flow of execution
• (hidden) WinMain runs
• InitInstance begins
– CMainFrame runs (does nothing in our case)
– Main window object (CREATESTRUCT) created
– PreCreateWindow
• Allows "filling-in" of struct values
• Window exists but is not displayed yet
• Sends WM_CREATE on ending
– OnCreate
• Creates a view to occupy the window
• Creates a status bar (if requested)
• Initialize your own variables here
• InitInstance ends – sends WM_PAINT
• OnPaint writes/draws text & graphics, shows screen
PreCreateWindow
• Optional settings
• "cs" is the name of the CREATESTRUCT passed
to the PreCreateWindow member
cs.lpszName = title; (a CString init'd here)
cs.x = 0;
//Y pos of window
cs.y = 0;
//X pos of window
cs.cx = 700;
//window width
cs.cy = 300;
//window height
OnCreate
• Most actions inserted by the Wizard
• Can now SetFont, use it's size
• Compute row positions for TextOut/DrawText
OnPaint
• Must do:
– CPaintDC dc(this);
• // Invalidate window so entire client area
• // is redrawn when UpdateWindow is called.
– Invalidate();
• // Update Window to cause View to redraw.
– UpdateWindow();
• MAY do this:
– SetFont(&myfont, true);
– dc.TextOut(formatted string);
Setting Font
VERIFY(myfont.CreateFont(
24,
// nHeight in points
0,
// nWidth
0,
// nEscapement
0,
// nOrientation
FW_NORMAL,
// nWeight
TRUE,
// bItalic
FALSE,
// bUnderline
0,
// cStrikeOut
ANSI_CHARSET,
// nCharSet
OUT_DEFAULT_PRECIS,
// nOutPrecision
CLIP_DEFAULT_PRECIS,
// nClipPrecision
DEFAULT_QUALITY,
// nQuality
DEFAULT_PITCH | FF_SWISS, // nPitchAndFamily
_T("Arial")));
// lpszFacename
SetFont(&myfont, true);
Debugging tips
• AfxMessageBox (_T("your message"));
• Be CAREFUL where you put AfxMessageBox.
– If it's in an OnMove, it will pop up for EVERY pixel of
the movement!!
– Same for OnPaint (pops up for each redraw)
– May need to test for !m_wndView in OnSetFocus
• Use a test to prevent multiple popups
• Win32API attribute "afx_msg" is empty:
–
–
–
–
E.g.; afx_msg int OnCreate(…)
"afx_msg" does not apply to MFC programs
Can be safely omitted when coding
Wizard keeps it for commonality
Window Creation
• Create new frame window object
CMainFrame* pFrame = new CMainFrame;
CMainFrame is the frame object
pFrame points to the object
• Set it as main window object
m_pMainWnd = pFrame;
• Load frame's resources
pFrame->LoadFrame(……parameters….)
Now show & update the window
• Notes:
–
–
–
–
"stdafx.h" includes "afxwin.h"
m_pMainWnd is defined in afxwin.h
Starting with version 3.0, all MFC classes are "thread safe" and
require the multi-threaded run-time libraries to link successfully.
Do NOT add: #include <windows.h> to your code
MFC-Hello sample
• MainFrm.cpp
– 1 message map (for CMainFrame class)
– handlers - on_wm_create() , on_wm_setfocus()
• MFC-hello.cpp
– 2 message maps (for CMFChelloApp class, for
CAboutDlg class)
– there are two message maps, because there are 2
classes, though the message map for the CAboutDlg
class does not have any handlers.
– rule is 1 map per class
• Childview.cpp - 1 message map for the cChildview
class.
Basic Structure of an MFC program
afxwin.h
MyWinApp.h
MainFrame.h
MainFrame.cpp
Main.cpp
MyWinApp.cpp
Using fonts
• CreateFont – allows specifying EVERYTHING
• CreatePointFont – specify only size & typeface
Cfont myfont;
myfont.CreateFont (…); or
myfont.CreatePointFont (…);
• Activate it:
– Method 1 (using a pointer to the context object)
CDC* dc; dc = GetDC();
CFont * fontptr = dc->SelectObject(&myfont);
– Method 2 (using the context object directly)
CPaintDC dc(this);// "this" is handle for current window
CFont * fontptr = dc.SelectObject(&myfont);
Resource (.rc) files
• Collection of UI elements
http://msdn.microsoft.com/en-us/library/y3sk7e6b.aspx
– Provide info to user
•
•
•
•
•
•
Icons
Bitmaps
Toolbars
Cursors
Dialogs
Accelerators
Resource files & their content
• Projname.rc
– toolbars, dialog boxes, etc.
– Accelerator and string tables.
– Default "About" dialog box.
• Resource.h
– definitions for the resources
• Projname.ico
– The icon file for the project or a control