Re: Re: Nullable CDateTimeCtrl?

Make a new class as below

Hope it helps you

..h
#pragma once

void AFXAPI DDX_DateTimeCtrl(CDataExchange* pDX, int nIDC, COleDateTime& value);

// CDateTimeEx

class CDateTimeEx : public CDateTimeCtrl
{
    DECLARE_DYNAMIC(CDateTimeEx)

public:
    CDateTimeEx();
    virtual ~CDateTimeEx();

protected:
    virtual BOOL PreTranslateMessage(MSG* pMsg);
    afx_msg void OnPopupDelete();
    afx_msg void OnDtnDatetimechange(NMHDR *pNMHDR, LRESULT *pResult);
    DECLARE_MESSAGE_MAP()

private:
    void ShowMenu(void);

public:
    unsigned int m_nIdCtrl;
    CWnd* m_pWnd;
};

..cpp
// DateTimeEx.cpp : implementation file
//

#include "stdafx.h"
#include "DateTimeEx.h"

void AFXAPI DDX_DateTimeCtrl(CDataExchange* pDX, int nIDC, COleDateTime& value)
{
    CDateTimeEx dt;
    CString strTemp;
    HWND hWndCtrl = pDX->PrepareCtrl(nIDC);
    CDateTimeCtrl* pWnd = (CDateTimeCtrl*) CWnd::FromHandle(hWndCtrl);

    ENSURE(pWnd);
    if (pDX->m_bSaveAndValidate)
    {
        int nLen = ::GetWindowTextLength(hWndCtrl);
        ::GetWindowText(hWndCtrl, strTemp.GetBufferSetLength(nLen), nLen+1);
        strTemp.ReleaseBuffer();

        if (strTemp.IsEmpty() || strTemp == _T(" "))
        {
            value.SetStatus(COleDateTime::null);
        }
        else
        {
            if (!value.ParseDateTime(strTemp)) // throws exception
            {
                value.SetStatus(COleDateTime::null);
                // Can't convert string to datetime
                AfxMessageBox(AFX_IDP_PARSE_DATETIME);
                pDX->Fail(); // throws exception
            }
        }
    }
    else
    {
        if (value.GetStatus() == COleDateTime::valid)
        {
            pWnd->SetFormat(NULL);
            pWnd->SetTime(value);
            strTemp = value.Format();
        }
        else
        {
            // Sets the time to the calendar
            pWnd->SetTime(COleDateTime::GetCurrentTime());
            // Clears the DateTime control
            pWnd->SetFormat(" ");
            strTemp = _T("");
            AfxSetWindowText(hWndCtrl, strTemp);
        }
    }
}

// CDateTimeEx

IMPLEMENT_DYNAMIC(CDateTimeEx, CDateTimeCtrl)

CDateTimeEx::CDateTimeEx()
: m_nIdCtrl(0)
, m_pWnd(NULL)
{

}

CDateTimeEx::~CDateTimeEx()
{
}

BEGIN_MESSAGE_MAP(CDateTimeEx, CDateTimeCtrl)
    ON_COMMAND(IDM_POPUP_DELETE, &CDateTimeEx::OnPopupDelete)
    ON_NOTIFY_REFLECT(DTN_DATETIMECHANGE, &CDateTimeEx::OnDtnDatetimechange)
END_MESSAGE_MAP()

// CDateTimeEx message handlers

BOOL CDateTimeEx::PreTranslateMessage(MSG* pMsg)
{
    BOOL bCtrlFound = FALSE;

    // Retreiving Control ID
    m_pWnd = FromHandle(pMsg->hwnd);
    if (m_pWnd != NULL)
    {
        m_nIdCtrl = m_pWnd->GetDlgCtrlID();
        bCtrlFound = TRUE;
    }

    switch (pMsg->message)
    {
    case WM_MOUSEMOVE:
        break;

    case WM_CHAR:
        break;

    case WM_LBUTTONDBLCLK:
        break;

    case WM_RBUTTONUP:
        break;

    case WM_RBUTTONDOWN:
        ShowMenu();
        break;

    case WM_LBUTTONDOWN:
        break;

    case WM_KEYDOWN:
        // No ESCAPE or RETURN Key
        if( pMsg->wParam == VK_RETURN || pMsg->wParam == VK_ESCAPE )
        {
            ::TranslateMessage(pMsg);
            ::DispatchMessage(pMsg);
            return FALSE; // DO NOT process further
        }
        break;

    // NO ALT+ key
    case WM_SYSCOMMAND:
        return TRUE;
        break;
    }

    return CDateTimeCtrl::PreTranslateMessage(pMsg);
}

// Shows the delete popup menu item
void CDateTimeEx::ShowMenu(void)
{
    int n = 0;

    // Popup menu
    CMenu popUpMenu;
    popUpMenu.CreatePopupMenu();
    popUpMenu.InsertMenu(n, MF_BYPOSITION, IDM_POPUP_DELETE, _T("Supprimer")); n++;

    CPoint p;
    GetCursorPos(&p);
    popUpMenu.TrackPopupMenu(TPM_CENTERALIGN | TPM_LEFTBUTTON,
                    p.x, p.y, (CWnd *) this, NULL);
}

// Clears window content
void CDateTimeEx::OnPopupDelete()
{
    SetFormat(" ");
    m_pWnd->SetWindowTextA(_T(""));
}

void CDateTimeEx::OnDtnDatetimechange(NMHDR *pNMHDR, LRESULT *pResult)
{
    LPNMDATETIMECHANGE pDTChange = reinterpret_cast<LPNMDATETIMECHANGE>(pNMHDR);
    // Sets format to default sytem date format
    SetFormat(NULL);
    *pResult = 0;
}