Double click handling on a CButton (using PreSubclassWindow)

#include "stdafx.h"
#include "ButtonEx.h"
#include "ButtonExDlg.h"

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


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()


CButtonExDlg::CButtonExDlg(CWnd* pParent /*=NULL*/)
: CDialog(CButtonExDlg::IDD, pParent)
{
    //{{AFX_DATA_INIT(CButtonExDlg)
    // 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 CButtonExDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CButtonExDlg)
    DDX_Control(pDX, IDC_BUTTON1, m_Button);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CButtonExDlg, CDialog)
//{{AFX_MSG_MAP(CButtonExDlg)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_BN_DOUBLECLICKED( IDC_BUTTON1, OnButtonDoubleClick )
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()



BOOL CButtonExDlg::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 < 0xF000);
    
    CMenu* pSysMenu = GetSystemMenu(FALSE);
    if (pSysMenu != NULL)
    {
        CString strAboutMenu;
        strAboutMenu.LoadString(IDS_ABOUTBOX);
        if (!strAboutMenu.IsEmpty())
        {
            pSysMenu->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);
    SetIcon(m_hIcon, FALSE);

    m_Button.ModifyStyle( 0, BS_NOTIFY );
    return TRUE;  // return TRUE  unless you set the focus to a control
}

void CButtonExDlg::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 CButtonExDlg::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 CButtonExDlg::OnQueryDragIcon()
{
    return (HCURSOR) m_hIcon;
}

void CButtonExDlg::OnButtonDoubleClick() 
{
    AfxMessageBox( _T( "Double clicked" ));
}