Changing the number of items that appear in the Most Recently Used List (MRU)

Introduction

This article explains how to change the number of files that are displayed in the list of most recently used files that is displayed in the File menu.

How is it done?

In the class derived from CWinApp in a SDI or MDI application created by the Application Wizard, there is an undocumented member m_pRecentFileList. This is an object of the class CRecentFileList. This is the class that is used to display the MRU files in the menu. The class does not provide anyway to change the size without deleting the class and recreating it. Below is the method that is used to accomplish this:

#include <afxadv.h>        // This must be included for the CRecentFileList class


BOOL CMRUAppApp::ChangeMRUCount(UINT nCount)
{
    BOOL bReturn = FALSE;

    ASSERT(nCount <= 16);        // Make sure value is not greater than 16


    // Make sure that the list is written to registry


    m_pRecentFileList->WriteList();

    // Get place in registry and format from original CRecentFileList


    CString strSection = m_pRecentFileList->m_strSectionName;
    CString strEntryFormat = m_pRecentFileList->m_strEntryFormat;

    // Delete current CRecentFileList


    delete m_pRecentFileList;

    // Create a new one 


    m_pRecentFileList = new CRecentFileList(0, strSection, strEntryFormat, nCount);

    ASSERT(m_pRecentFileList);

    if(m_pRecentFileList)
    {
        bReturn = TRUE;

        // Reload list of MRU files from registry


        m_pRecentFileList->ReadList();
    }

    return bReturn;

Points of interest

To be able to compile the code to use the m_pRecentFileList object, you must include the header afxadv.h.

The first thing the method does is to store the section in the registry or application INI file where the MRU file list is stored and to get the string that is used to format the name of the entries stored in the registry. The current object is then deleted and a new one created using these stored values and the count of MRU files that was sent to the method. If this was created successfully then the list is read back from the registry or INI file.

You can only have a maximum of 16 items in the list.