CComboBox with support for history

Environment: VC6

Introduction

The History Combo class CHistoryCombo is based on CComboBox, and includes support
for keeping item history, including reading from and saving to the registry.
It can also be used to display the contents of an existing CRecentFileList object.

How to use it

Using the CHistoryCombo class is very straightforward. Follow the steps below
to add one to an existing project.

1. After putting the source files (HistoryCombo.cpp and HistoryCombo.h) into
the directory you wish to use them from, add the files to your Visual Studio
project.

2. In the resource editor, add a combo where you wish.

3. In Class Wizard add a member variable for your combo control, selecting
"Control" from the "Category" list, and selecting "CHistoryCombo"
from the "Variable Type" list. (If CHistoryCombo does not appear in
the list, you may need to delete your class wizard file (.clw) and regenerate
it). I will assume your control variable name is m_comboHistory.

4. Add a handler for WM_INITDIALOG in your dialog class if you don’t already
have one, and add the following code to it:

m_comboHistory.LoadHistory("Settings", "HistoryCombo");

(Note: you can specify any strings you wish for the section, and key-prefix)

5. In your handler for the IDOK button, or whereever you choose, add the following:

m_comboHistory.SaveHistory();

That’s all you need to do.

Documentation

Each function is documented in the cpp file. Here is a list of functions
in CHistoryCombo:

CHistoryCombo(BOOL bAllowSortStyle = FALSE);

CString LoadHistory(LPCTSTR lpszSection,
                    LPCTSTR lpszKeyPrefix,
                    BOOL bSaveRestoreLastCurrent = TRUE,
                    LPCTSTR lpszKeyCurItem = NULL);

CString LoadHistory(CRecentFileList* pListMRU,
                    BOOL bSelectMostRecent = TRUE);

void SaveHistory(BOOL bAddCurrentItemtoHistory = TRUE);

int AddString(LPCTSTR lpszString);

void SetMaxHistoryItems(int nMaxItems);

void ClearHistory(BOOL bDeleteRegistryEntries = TRUE);

void StoreValue(BOOL bIgnoreIfEmpty = TRUE);

Downloads

Download source – 4.52 Kb

Download demo – 118 Kb

May 8, 2002 – Version 2

• removed CBS_SORT on creation if specified
• added option to allow the sort style to be set if required
• fixed SetMaxHistoryItems, so it removes old entries from the list to
  ensure that there are no more than the maximum. Also made SaveHistory remove
  redundant profile entries above the maximum.
• use WriteProfileString to remove profile entries rather than CRegKey.

April 12, 2001 – First Version