Hello,

Ive a legacy combobox of CBS_DROPDOWN type.

And somehow, user typed value is not getting updated.

I tried to write a small example code in VS2015, where, the event handler doesnot get called, on writting a text to combo box:
Any suggestions on this is very helpful

Code:

// MFCApplication3Dlg.h : header file
//

#pragma once
#include "afxwin.h"


// CMFCApplication3Dlg dialog
class CMFCApplication3Dlg : public CDialogEx
{
// Construction
public:
	CMFCApplication3Dlg(CWnd* pParent = NULL);	// standard constructor

// Dialog Data
#ifdef AFX_DESIGN_TIME
	enum { IDD = IDD_MFCAPPLICATION3_DIALOG };
#endif

	protected:
	virtual void DoDataExchange(CDataExchange* pDX);	// DDX/DDV support


// Implementation
protected:
	HICON m_hIcon;

	// Generated message map functions
	virtual BOOL OnInitDialog();
	afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
	afx_msg void OnPaint();
	afx_msg HCURSOR OnQueryDragIcon();
	DECLARE_MESSAGE_MAP()
public:
	CComboBox m_sim;
	CString m_val;
	afx_msg void OnCbnSelchangeCombo1();
	afx_msg void OnCbnSelchangeCombo2();
};



.cpp


// MFCApplication3Dlg.cpp : implementation file
//

#include "stdafx.h"
#include "MFCApplication3.h"
#include "MFCApplication3Dlg.h"
#include "afxdialogex.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// CAboutDlg dialog used for App About

class CAboutDlg : public CDialogEx
{
public:
	CAboutDlg();

// Dialog Data
#ifdef AFX_DESIGN_TIME
	enum { IDD = IDD_ABOUTBOX };
#endif

	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support

// Implementation
protected:
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialogEx(IDD_ABOUTBOX)
{
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialogEx)
END_MESSAGE_MAP()


// CMFCApplication3Dlg dialog



CMFCApplication3Dlg::CMFCApplication3Dlg(CWnd* pParent /*=NULL*/)
	: CDialogEx(IDD_MFCAPPLICATION3_DIALOG, pParent)
{
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMFCApplication3Dlg::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
	DDX_Control(pDX, IDC_COMBO1, m_sim);
}

BEGIN_MESSAGE_MAP(CMFCApplication3Dlg, CDialogEx)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_CBN_SELCHANGE(IDC_COMBO1, &CMFCApplication3Dlg::OnCbnSelchangeCombo1)
	ON_CBN_SELCHANGE(IDC_COMBO2, &CMFCApplication3Dlg::OnCbnSelchangeCombo2)
END_MESSAGE_MAP()


// CMFCApplication3Dlg message handlers

BOOL CMFCApplication3Dlg::OnInitDialog()
{
	CDialogEx::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)
	{
		BOOL bNameValid;
		CString strAboutMenu;
		bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX);
		ASSERT(bNameValid);
		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);			// 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 CMFCApplication3Dlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialogEx::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 CMFCApplication3Dlg::OnPaint()
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<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
	{
		CDialogEx::OnPaint();
	}
}

// The system calls this function to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CMFCApplication3Dlg::OnQueryDragIcon()
{
	return static_cast<HCURSOR>(m_hIcon);
}




void CMFCApplication3Dlg::OnCbnSelchangeCombo1()
{
	int item = m_sim.GetCurSel();

	int sel = m_sim.GetCurSel();
	if (sel == -1)
	{
		CString str;
		m_sim.GetWindowTextW(str);
	}
	//if (sel == -1)
	//{
	//	int len = m_sim.GetWindowTextLength() + 1;
	//	string tp = new char[len];
	//	m_sim.GetWindowTextA(tp, len);
	//	sel = m_sim.FindStringExact(-1, tp);
	//	if (sel == -1)
	//	{
	//		sel = wnd.InsertString(0, tp);
	//		wnd.SetCurSel(sel);
	//	}
	//	int cnt;
	//	while ((cnt = wnd.GetCount()) >= 20)
	//		wnd.DeleteString(cnt - 1);
	//}
	else
	{
		m_sim.GetLBText(m_sim.GetCurSel(), m_val);
		UpdateData(FALSE);
	}
	//if (item != CB_ERR)
	//{
	//	CString text;
	//	m_sim.GetLBText(item, text);
	//}
	// TODO: Add your control notification handler code here
}

void CMFCApplication3Dlg::OnCbnSelchangeCombo2()
{
	int i = 0;
	// TODO: Add your control notification handler code here
}