VSTO Excel Com Add In Ribbon Not Loading

Question

I'm using VS 2010 to develop an Excel 2007 COM Add-In. Because it's a VS 2010 Office Project, it targets the .NET 4.0 Client Framework. I've added a new Ribbon (XML) item called MyRibbon, so default filenames of ThisAddIn.cs, MyRibbon.cs, and MyRibbon.xml.

Everything builds fine. It publishes with a .vsto extension. When I install the add-in (via the provided Setup.exe) it takes in Excel as being installed, and is checked in the COM Add-Ins list. It also is designated to load on start up. However, either opening Excel first or opening an Excel file does not add the tab to the ribbon.

I can tell the Add-In loads because it puts "COM add-in loaded" in the first cell of the first sheet. It appears as though CreateRibbonExtensibilityObject() is not getting called.

Does anyone have any ideas, or could tell me how to display any error messages that might be getting buried?

Details below.

I've added the override of CreateRibbonExtensibilityObject():

protected override Office.IRibbonExtensibility CreateRibbonExtensibilityObject()
        {
            return new MyRibbon();
        }

MyRibbon.xml looks like this, three buttons in a group inside of a tab:

<?xml version="1.0" encoding="UTF-8"?>
<customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui" onLoad="Ribbon_Load">
  <ribbon>
    <tabs>
      <tab id="TabAdvComTracking" idMso="TabAdvComTrackingMso" label="Adv.com Tracking">
        <group id="groupPrepare" label="Prepare">
          <button id="GenerateNewWorkbook" idMso="GenerateNewWorkbookMso" enabled="1" size="large" onAction="GenNewWorkbook" label="Make"  />
          <separator visible="1"/>
          <button id="ClearData" idMso="ClearDataMso" enabled="1" size="large" onAction="ClearData" label="Clear" />
        </group>
        <group id="GroupDoIt" idMso="GroupDoItMso" label="Just Do It">
          <button id="CaptureIds" idMso="CaptureIdsMso" enabled="1" size="large" onAction="CaptureData" label="Eat" />
        </group>
      </tab>
    </tabs>
  </ribbon>
</customUI>

MyRibbon.cs looks like this:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using Office = Microsoft.Office.Core;
using Excel = Microsoft.Office.Interop.Excel;

namespace AdvComTrackingAddIn
{
    [ComVisible(true)]
    public class MyRibbon : Office.IRibbonExtensibility
    {
        private Office.IRibbonUI ribbon;

        public MyRibbon()
        {
        }

        #region IRibbonExtensibility Members

        public string GetCustomUI(string ribbonID)
        {
            //ribbonID when loaded into Excel should be Microsoft.Excel.Workbook
            return GetResourceText("AdvComTrackingAddIn.MyRibbon.xml");
        }

        #endregion

        #region Ribbon Callbacks
        //Create callback methods here. For more information about adding callback methods, select the Ribbon XML item in Solution Explorer and then press F1

        public void Ribbon_Load(Office.IRibbonUI ribbonUI)
        {
            this.ribbon = ribbonUI;
        }

        public void GenNewWorkbook(Office.IRibbonControl control)
        {
            Excel.Workbook newWorkBook = Globals.ThisAddIn.Application.Workbooks.Add();

            Excel.Worksheet newWorkSheet = (Excel.Worksheet)newWorkBook.Worksheets.Add();
            newWorkSheet.Name = "DBTS " + GetDateRange("MMDDYYYY");


        }

        public string GetDateRange(string format){
            string day = DateTime.Now.DayOfWeek.ToString();
            int offSet = 0;
            if(day == "Sunday") offSet = 1;
            else if(day == "Monday") offSet = 0;
            else if(day == "Tuesday") offSet = -1;
            else if(day == "Wednesday") offSet = -2;
            else if(day == "Thursday") offSet = -3;
            else if(day == "Friday") offSet = -4;
            else if(day == "Saturday") offSet = -5;

            DateTime MondayStartDate = DateTime.Now.AddDays(offSet);           

            return MondayStartDate.ToString(format) + "_" + MondayStartDate.AddDays(4).ToString(format);                
        }

        public void ClearData(Office.IRibbonControl control)
        {
            Excel.Sheets wksheets  = Globals.ThisAddIn.Application.Worksheets;
            Excel.Worksheet sheet;

            for(int i = 0; i < wksheets.Count; i++){
                sheet = wksheets[i];
                if(sheet.Name.StartsWith("DBTS")){
                    sheet.get_Range("A6:H12").Clear();
                    sheet.get_Range("A16:D22").Clear();
                    sheet.get_Range("A26:D10000").Clear();
                }
                else if(sheet.Name == "Advisory.com Activity"){
                    sheet.get_Range("A4:B10000").Clear();
                    sheet.get_Range("D4:F10000").Clear();
                    sheet.get_Range("H4:J10000").Clear();
                }
                else if(sheet.Name == "Unique Hits Per URL"){
                    sheet.get_Range("A4:E10000").Clear();
                }
            }            
        }

        public void CaptureData(Office.IRibbonControl control)
        {
        }

        #endregion

        #region Helpers

        private static string GetResourceText(string resourceName)
        {
            Assembly asm = Assembly.GetExecutingAssembly();
            string[] resourceNames = asm.GetManifestResourceNames();
            for (int i = 0; i < resourceNames.Length; ++i)
            {
                if (string.Compare(resourceName, resourceNames[i], StringComparison.OrdinalIgnoreCase) == 0)
                {
                    using (StreamReader resourceReader = new StreamReader(asm.GetManifestResourceStream(resourceNames[i])))
                    {
                        if (resourceReader != null)
                        {
                            return resourceReader.ReadToEnd();
                        }
                    }
                }
            }
            return null;
        }

        #endregion
    }
}

Finally, ThisAddIn.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using Excel = Microsoft.Office.Interop.Excel;
using Office = Microsoft.Office.Core;
using Microsoft.Office.Tools.Excel;
using System.IO;
using System.Reflection;

namespace AdvComTrackingAddIn
{
    public partial class ThisAddIn
    {
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            Globals.ThisAddIn.Application.get_Range("A1").Value = "COM add-in loaded";
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
            GC.Collect();
        }

        protected override Office.IRibbonExtensibility CreateRibbonExtensibilityObject()
        {
            return new MyRibbon();
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }

        #endregion
    }
}

Answer 1

I encountered the same problem. I had an incorrect path to the XML file and it was returning empty:

 public string GetCustomUI(string ribbonID)
 {
    return GetResourceText("CheckThisIsTheCorrectNameSpace.Ribbon.xml");
 }

Hard coding a Namespace as a string is not a good idea, mainly because they are not refactor-able as well as the helpful comments below.