Dynamic control | create command button control and notification handler during runtime

OBJECTIVE:
To create a command button control and a notification handler during runtime.
PROCEDURE:
1. Run MFC Appwizard(exe)to generate C:\Dyn.
2. Select Dialog based from step1 of the Appwizard.
3. Select all the other default settings and press the finish button.
4. Delete all the command buttons & the static text of dialog.
5. In DynDlg.h declare a variable mybutton of CButton class.
class CDynDlg : public CDialog
{
public:
CButton mybutton;
6. Using class wizard map the object CDynDlg with the message WM_LBUTTONDOWN and a notification handler OnLButtonDown() will be created.IndynDlg.cpp type the following
void CDynDlg::OnLButtonDown(UINT nFlags, CPoint point)
{
mybutton.Create("dynamic",WS_CHILDWS_VISIBLE,CRect(10,10,100,40),this,IDOK);
CDialog::OnLButtonDown(nFlags, point);uuuuu
}
and define the IDC_BUTTON as #define IDC_BUTTON in Dyndlg.cpp
#define IDC_BUTTON1
7. In DynDlg.h declare the user defined handler in the AFX_MSG
//{{AFX_MSG(CDynDlg)
virtual BOOL OnInitDialog();
afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
afx_msg void OnPaint();
afx_msg HCURSOR OnQueryDragIcon();
afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
afx_msg void handlefunction();
afx_msg void OnButton1();
//}}AFX_MSG
8. In DynDlg.cpp declare message map ON_BN_CLICKED with IDC_BUTTON to the handler handle function as follows.
//{{AFX_MSG_MAP(CDynDlg)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_WM_LBUTTONDOWN()
ON_BN_CLICKED(IDOK,handlefunction)
ON_BN_CLICKED(IDC_BUTTON1, OnButton1)
//}}AFX_MSG_MAP
9. Type the following in the end of the DynDlg.cpp as follows
void CDynDlg::handlefunction()
{
MessageBox("dynamic control created","WELCOME",MB_OK);
}
10. Compile,run & test the application.
PROGRAM:
SOURCE FILES:
DynDlg.cpp
// dynDlg.cpp : implementation file

 

#define IDC_BUTTON1
#include "stdafx.h"
#include "dyn.h"
#include "dynDlg.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About
class CAboutDlg : public CDialog
{
public:
CAboutDlg();

// Dialog Data
//{{AFX_DATA(CAboutDlg)
enum { IDD = IDD_ABOUTBOX };
//}}AFX_DATA
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CAboutDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL
// Implementation
protected:
//{{AFX_MSG(CAboutDlg)
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
//{{AFX_DATA_INIT(CAboutDlg)
//}}AFX_DATA_INIT
}
void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CAboutDlg)
//}}AFX_DATA_MAP
}
BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
//{{AFX_MSG_MAP(CAboutDlg)
// No message handlers
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CDynDlg dialog
CDynDlg::CDynDlg(CWnd* pParent /*=NULL*/)
: CDialog(CDynDlg::IDD, pParent)
{
//{{AFX_DATA_INIT(CDynDlg)
// NOTE: the ClassWizard will add member initialization here
//}}AFX_DATA_INIT
// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}
void CDynDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CDynDlg)
// NOTE: the ClassWizard will add DDX and DDV calls here
//}}AFX_DATA_MAP
}
BEGIN_MESSAGE_MAP(CDynDlg, CDialog)
//{{AFX_MSG_MAP(CDynDlg)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_WM_LBUTTONDOWN()
ON_BN_CLICKED(IDOK,handlefunction)
ON_BN_CLICKED(IDC_BUTTON1, OnButton1)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CDynDlg message handlers

BOOL CDynDlg::OnInitDialog()
{
CDialog::OnInitDialog();
// Add "About..." menu item to system menu.
// IDM_ABOUTBOX must be in the system command range.
ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
ASSERT(IDM_ABOUTBOX < psysmenu =" GetSystemMenu(FALSE);">AppendMenu(MF_SEPARATOR);
pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
}
}
// Set the icon for this dialog. The framework does this automatically
// when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE); // Set big icon
SetIcon(m_hIcon, FALSE); // Set small icon
// TODO: Add extra initialization here
return TRUE; // return TRUE unless you set the focus to a control
}

void CDynDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
if ((nID & 0xFFF0) == IDM_ABOUTBOX)
{
CAboutDlg dlgAbout;
dlgAbout.DoModal();
}
else
{
CDialog::OnSysCommand(nID, lParam);
}
}
// If you add a minimize button to your dialog, you will need the code below
// to draw the icon. For MFC applications using the document/view model,
// this is automatically done for you by the framework.
void CDynDlg::OnPaint()
{
if (IsIconic())
{
CPaintDC dc(this); // device context for painting

SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

// Center icon in client rectangle
int cxIcon = GetSystemMetrics(SM_CXICON);
int cyIcon = GetSystemMetrics(SM_CYICON);
CRect rect;
GetClientRect(&rect);
int x = (rect.Width() - cxIcon + 1) / 2;
int y = (rect.Height() - cyIcon + 1) / 2;

// Draw the icon
dc.DrawIcon(x, y, m_hIcon);
}
else
{
CDialog::OnPaint();
}
}
// The system calls this to obtain the cursor to display while the user drags the minimized window.
HCURSOR CDynDlg::OnQueryDragIcon()
{
return (HCURSOR) m_hIcon;
}
void CDynDlg::OnLButtonDown(UINT nFlags, CPoint point)
{
mybutton.Create("dynamic",WS_CHILDWS_VISIBLE,CRect(10,10,100,40),this,IDOK);
CDialog::OnLButtonDown(nFlags, point);
}
void CDynDlg::handlefunction()
{
MessageBox("dynamic control created","WELCOME",MB_OK);
}
HEADER FILES:

DynDlg.h
// dynDlg.h : header file
#if !defined(AFX_DYNDLG_H__1BBAB239_4D39_4463_B4B6_5F4795643128__INCLUDED_)
#define AFX_DYNDLG_H__1BBAB239_4D39_4463_B4B6_5F4795643128__INCLUDED_
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
/////////////////////////////////////////////////////////////////////////////
// CDynDlg dialog
class CDynDlg : public CDialog
{
// Construction
public:
CButton mybutton;
CDynDlg(CWnd* pParent = NULL); // standard constructor
// Dialog Data
//{{AFX_DATA(CDynDlg)
enum { IDD = IDD_DYN_DIALOG };
// NOTE: the ClassWizard will add data members here
//}}AFX_DATA
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CDynDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL
// Implementation
protected:
HICON m_hIcon;
// Generated message map functions
//{{AFX_MSG(CDynDlg)
virtual BOOL OnInitDialog();
afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
afx_msg void OnPaint();
afx_msg HCURSOR OnQueryDragIcon();
afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
afx_msg void handlefunction();
afx_msg void OnButton1();
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};