www.pudn.com > ComboBoxExample.rar > ComboBoxEx.cpp

// ComboBoxEx.cpp : implementation file 
// 
// Autocompleting combo-box (like the URL edit box in netscape) 
// 
// Written by Chris Maunder (Chris.Maunder@cbr.clw.csiro.au) 
// Copyright (c) 1998. 
// 
// This code may be used in compiled form in any way you desire. This 
// file may be redistributed unmodified by any means PROVIDING it is  
// not sold for profit without the authors written consent, and  
// providing that this notice and the authors name is included. If  
// the source code in  this file is used in any commercial application  
// then acknowledgement must be made to the author of this file  
// (in whatever form you wish). 
// 
// This file is provided "as is" with no expressed or implied warranty. 
// The author accepts no liability if it causes any damage to your 
// computer, causes your pet cat to fall ill, increases baldness or 
// makes you car start emitting strange noises when you start it up. 
// 
// Expect bugs. 
//  
// Please use and enjoy. Please let me know of any bugs/mods/improvements  
// that you have found/implemented and I will fix/incorporate them into this 
// file.  
// 
// Modified: 12 Sep 1998 Setting correct cursor position after  
//                       auto-complete: Petr Stejskal and Ryan Schneider 
// 
// 本代码供免费使用，使用时请遵守如上协定 
///////////////////////////////////////////////////////////////////////////// 
 
#include "stdafx.h" 
#include "ComboBoxEx.h" 
 
#ifdef _DEBUG 
#define new DEBUG_NEW 
#undef THIS_FILE 
static char THIS_FILE[] = __FILE__; 
#endif 
 
///////////////////////////////////////////////////////////////////////////// 
// CComboBoxExt 
 
CComboBoxExt::CComboBoxExt() 
{ 
	m_bAutoComplete = TRUE; 
} 
 
CComboBoxExt::~CComboBoxExt() 
{ 
} 
 
 
BEGIN_MESSAGE_MAP(CComboBoxExt, CComboBox) 
//{{AFX_MSG_MAP(CComboBoxExt) 
ON_CONTROL_REFLECT(CBN_EDITUPDATE, OnEditUpdate) 
//}}AFX_MSG_MAP 
END_MESSAGE_MAP() 
 
///////////////////////////////////////////////////////////////////////////// 
// CComboBoxExt message handlers 
 
BOOL CComboBoxExt::PreTranslateMessage(MSG* pMsg) 
{ 
	// Need to check for backspace/delete. These will modify the text in 
	// the edit box, causing the auto complete to just add back the text 
	// the user has just tried to delete.  
	 
	if (pMsg->message == WM_KEYDOWN) 
	{ 
		m_bAutoComplete = TRUE; 
		 
		int nVirtKey = (int) pMsg->wParam; 
		if (nVirtKey == VK_DELETE || nVirtKey == VK_BACK) 
			m_bAutoComplete = FALSE; 
	} 
	 
	return CComboBox::PreTranslateMessage(pMsg); 
} 
 
void CComboBoxExt::OnEditUpdate()  
{ 
	// if we are not to auto update the text, get outta here 
	if (!m_bAutoComplete)  
		return; 
	 
	// Get the text in the edit box 
	CString str; 
	GetWindowText(str); 
	int nLength = str.GetLength(); 
	 
	// Currently selected range 
	DWORD dwCurSel = GetEditSel(); 
	WORD dStart = LOWORD(dwCurSel); 
	WORD dEnd   = HIWORD(dwCurSel); 
	 
	// Search for, and select in, and string in the combo box that is prefixed 
	// by the text in the edit box 
	if (SelectString(-1, str) == CB_ERR) 
	{ 
		SetWindowText(str);		// No text selected, so restore what was there before 
		if (dwCurSel != CB_ERR) 
			SetEditSel(dStart, dEnd);	//restore cursor postion 
	} 
	 
	// Set the text selection as the additional text that we have added 
	if (dEnd < nLength && dwCurSel != CB_ERR) 
		SetEditSel(dStart, dEnd); 
	else 
		SetEditSel(nLength, -1); 
}