Excel VSTO access sheet name through ThisAddIn StartUp

Question

I am stuck and hoping to get some help here. I have an Excel VSTO add-in with a ribbon that contains various controls. I would like to have all but one control disabled unless a sheet with a specific name is active. How is this accomplished? So far, I figured out how to map the ribbon button to the ThisAddIn startup in order to keep it active, while the other buttons default to disabled:

RibbonButton btx_newECO = Globals.Ribbons.Ribbon1.btn_ECOnumber;
btx_newECO.Enabled = true;

Now, how do I enable the other ribbon buttons when the sheet with a specific name is opened? `

Answer 1

Okay, Cindy got me going in the right direction. Rather than using a SheetActivateHandler I used a WorkBookOpenHandler. I had no idea I could assign event handlers this way. I totally learned this today. Thanks, Cindy :)

--ThisAddIn---

public partial class ThisAddIn
{
    Ribbon1 rbn;
    string triggerName = "ECO";

    #region StartUp
    private void ThisAddIn_Startup(object sender, System.EventArgs e)
    {
        //detect the sheet name on workbook open event
        rbn = Globals.Ribbons.Ribbon1;
        this.Application.WorkbookOpen+= new Excel.AppEvents_WorkbookOpenEventHandler(Application_WorkbookOpen);
    }

    #endregion

    #region Enable Ribbon Buttons
    void Application_WorkbookOpen(object Sh)
    {
        Excel.Worksheet ws = (Excel.Worksheet)Globals.ThisAddIn.Application.ActiveSheet;
        if (ws.Name == triggerName)
        {
            rbn.btn_ECOnumber.Enabled = false;
        } 
    }
    #endregion

---Shutdown and VSTO generated Code here-----