线程安全ReferenceEquals

Question

I try to create an VSTO Addin. Within this I store Worksheet objects in a list. For my Addin it is important to use a delayed function call to execute it in a own Thread. So when I call TestClass.run() I go 2 times through my list of worksheets, first before calling the delayed function and second within the delayed function. The second call cannot match the worksheet instance. How can I achieve this?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Office.Interop.Excel;
using System.Timers;

namespace Ventron.VRange
{
    public class TestClass
    {
        private static List<OuterWorksheet> sheetList = new List<OuterWorksheet>();

        public static void run(Range range)
        {
            TestClass.sheetList.Add(new OuterWorksheet(range.Worksheet));
            TestClass.getWorkSheet(range.Worksheet);

            ElapsedEventHandler delayedFn = delegate(object sender, ElapsedEventArgs e)
            {
                System.Timers.Timer theTimer = (System.Timers.Timer)sender;
                if (theTimer.Enabled)
                {
                    theTimer.Stop();
                    theTimer.Enabled = false;
                    theTimer.Dispose();
                    theTimer = null;
                    TestClass.getWorkSheet(range.Worksheet);
                }
            };

            System.Timers.Timer timerInstance = new System.Timers.Timer(1);
            timerInstance.Elapsed += new System.Timers.ElapsedEventHandler(delayedFn);
            timerInstance.Interval = 1;
            timerInstance.Enabled = true;
        }

        internal static OuterWorksheet getWorkSheet(Worksheet worksheet)
        {
            System.Diagnostics.Debug.Write("*****************************\n");
            System.Diagnostics.Debug.Write(worksheet.CodeName + "\n");

            foreach (OuterWorksheet outerWS in TestClass.sheetList)
            {
                System.Diagnostics.Debug.Write(outerWS.worksheet.CodeName + "\n");
                if (outerWS.worksheet.Equals(worksheet))
                {
                    System.Diagnostics.Debug.Write("Worksheets are equal\n");
                    return outerWS;
                } else
                    System.Diagnostics.Debug.Write("Worksheets are not equal\n");
            }
            return null;
        }

        internal class OuterWorksheet
        {
            public Worksheet worksheet { get; private set; }
            public OuterWorksheet(Worksheet worksheet)
            {
                this.worksheet = worksheet;
            }
        }
    }
}

Output is:

*****************************
Sheet5
Sheet5
Worksheets are equal

*****************************
Sheet5
Sheet5
Worksheets are not equal

Thx!

Answer 1

Each time you are getting a worksheet, it is generating a new wrapper instance around the COM object that is exposed by excel, so they are never equal by reference. Excel requires unique sheet names, so just compare the names when you are checking for equality.