c# – 如何在.NET中检查文件当前是打开还是正在写入？

我正在尝试确定文件当前是打开还是使用C#写入.我已经看到类似的SO问题,所有问题都与我的代码类似,它在文件上尝试File.Open.但是当我使用下面的代码运行程序时,我也手动打开文件,我得到“文件当前未锁定”的意外结果.有什么想法/建议/我遗失的任何东西？

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Threading;

namespace TestIfFileAccessed
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = @"C:TEMPtestFile.txt";
            FileInfo filepath = new FileInfo(path);

            if (IsFileLocked(filepath)) {
                Console.WriteLine("File is currently locked");
                Console.ReadLine();
            }
            else
            {
                Console.WriteLine("File is currently NOT locked");
                Console.ReadLine();
            }
        }

        public static bool IsFileLocked(FileInfo file)
        {
            FileStream stream = null;

            try
            {
                stream = file.Open(FileMode.Open,FileAccess.ReadWrite,FileShare.None);
            }
            catch (IOException)
            {
                //the file is unavailable because it is:
                //still being written to
                //or being processed by another thread
                //or does not exist (has already been processed)
                return true;
            }
            finally
            {
                if (stream != null)
                    stream.Close();
            }

            //file is not locked
            return false;
        }
    }
}