Recently used files—Command, MultiItem, and ComboBox
ToolbarRecentFiles.cs
// Copyright 2010 ESRI
// 
// All rights reserved under the copyright laws of the United States
// and applicable international laws, treaties, and conventions.
// 
// You may freely redistribute and use this sample code, with or
// without modification, provided you include the original copyright
// notice and use restrictions.
// 
// See the use restrictions.
// 

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using ESRI.ArcGIS.ADF.CATIDs;
using ESRI.ArcGIS.ADF.BaseClasses;

namespace RecentFilesCommandsCS
{
    /// <summary>
    /// Summary description for ToolbarRecentFiles.
    /// </summary>
    [Guid("96112deb-333b-4f61-b7a7-a8a2f5fe6ad1")]
    [ClassInterface(ClassInterfaceType.None)]
    [ProgId("RecentFilesCommandsCS.ToolbarRecentFiles")]
    public sealed class ToolbarRecentFiles : BaseToolbar
    {
        #region COM Registration Function(s)
        [ComRegisterFunction()]
        [ComVisible(false)]
        static void RegisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryRegistration(registerType);
        }

        [ComUnregisterFunction()]
        [ComVisible(false)]
        static void UnregisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryUnregistration(registerType);
        }

        #region ArcGIS Component Category Registrar generated code
        /// <summary>
        /// Required method for ArcGIS Component Category registration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryRegistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            MxCommandBars.Register(regKey);
            GMxCommandBars.Register(regKey);
            SxCommandBars.Register(regKey);

        }
        /// <summary>
        /// Required method for ArcGIS Component Category unregistration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryUnregistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            MxCommandBars.Unregister(regKey);
            GMxCommandBars.Unregister(regKey);
            SxCommandBars.Unregister(regKey);

        }

        #endregion
        #endregion

        public ToolbarRecentFiles()
        {
            AddItem("{4e0552c8-ee58-4dda-b6be-c4eb6b9dd690}");
            AddItem("RecentFilesCommandsCS.RecentFilesCombo");
        }

        public override string Caption
        {
            get
            {
                return "Recent Files (C#)";
            }
        }
        public override string Name
        {
            get
            {
                return "CSNETSamples_RecentFilesToolbar";
            }
        }
    }
}