Filesystemwatcher 不会在 Windows7 上的 C# 中引发重命名事件处理程序

Question

我在 Windows 7 上使用 C# 3.5。我们已经实现了一个带有 FileSystemWatcher 的程序。在这里，不会引发重命名事件。但它正在一些系统上运行。

这可能是什么原因造成的？

Answer 1

您的代码中可能存在一个计时窗口，因此并非所有文件系统事件都可以在您的所有系统上正确捕获。可以发一下吗？

这是底层 Win32 API ReadDirectoryChangesW 和 FileSystemWatcher 的“功能”，在重负载下，可能会错过事件。 MSDN docs 中有缓解建议。

Answer 2

确保您设置了观察者：

fileSystemWatcher.EnableRaisingEvents = true;

Answer 3

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Security.AccessControl;
using System.Security.Permissions;
using System.Text;
using System.Windows.Forms;

namespace Watcher
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            FileRenamed();           
        }

        private static string _osLanguage = null;
        [PermissionSet(SecurityAction.Demand, Name = "FullTrust")] 

        private void FileRenamed()
        {
            MessageBox.Show("Code is Started Now");
            // Create a new FileSystemWatcher and set its properties.
            FileSystemWatcher watcher = new FileSystemWatcher();

            SetDirectoryAccess(@"c:\temp");

            watcher.Path = @"C:\Temp";

            /* Watch for changes in LastAccess and LastWrite times, and
               the renaming of files or directories. */
            watcher.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite
               | NotifyFilters.FileName | NotifyFilters.DirectoryName;

            // Only watch text files.
            watcher.Filter = "*.txt";

            // Add event handlers.
            watcher.Changed += new FileSystemEventHandler(OnChanged);
            watcher.Created += new FileSystemEventHandler(OnChanged);
            watcher.Deleted += new FileSystemEventHandler(OnChanged);
            watcher.Renamed += new RenamedEventHandler(OnRenamed);
            watcher.Error += new ErrorEventHandler(OnError);

            // Begin watching.
            watcher.EnableRaisingEvents = true;

        }

        // Define the event handlers.
        private static void OnChanged(object source, FileSystemEventArgs e)
        {
            // Specify what is done when a file is changed, created, or deleted.
            //Console.WriteLine("File: " + e.FullPath + " " + e.ChangeType);
            MessageBox.Show("Something is changed in the File");
        }

        private static void OnRenamed(object source, RenamedEventArgs e)
        {
            // Specify what is done when a file is renamed.
            MessageBox.Show("File Is Renamed");
            //WatcherChangeTypes wct = e.ChangeType;
            //Console.WriteLine("File {0} {2} to {1}", e.OldFullPath, e.FullPath, wct.ToString());
        }


        //  This method is called when the FileSystemWatcher detects an error.
        private static void OnError(object source, ErrorEventArgs e)
        {
            MessageBox.Show("Error Trapped");
            //  Show that an error has been detected.
            Console.WriteLine("The FileSystemWatcher has detected an error");
            //  Give more information if the error is due to an internal buffer overflow.
            if (e.GetException().GetType() == typeof(InternalBufferOverflowException))
            {
                //  This can happen if Windows is reporting many file system events quickly 
                //  and internal buffer of the  FileSystemWatcher is not large enough to handle this
                //  rate of events. The InternalBufferOverflowException error informs the application
                //  that some of the file system events are being lost.
                Console.WriteLine(("The file system watcher experienced an internal buffer overflow: " + e.GetException().Message));
            }
        }


        private void button1_Click(object sender, EventArgs e)
        {
            //File.Move(@"\\NAS\dossier_echange\Carl\temp\Test.txt", @"\\NAS\dossier_echange\Carl\temp\Test007.txt"); 
            File.Move(@"c:\temp\Test.txt", @"c:\temp\Test007.txt"); 
        }

        internal static void SetDirectoryAccess(string directoryPathString)
        {
            string everyoneString;

            if (OSLanguage.Equals("en-US"))
                everyoneString = "Everyone";
            else
                everyoneString = "Tout le monde";

            //sets the directory access permissions for everyone
            DirectorySecurity fileSecurity = Directory.GetAccessControl(directoryPathString);
            //creates the access rule for directory
            fileSecurity.ResetAccessRule(new FileSystemAccessRule(everyoneString, FileSystemRights.FullControl, AccessControlType.Allow));
            //sets the access rules for directory
            Directory.SetAccessControl(directoryPathString, fileSecurity);
        }

        public static string OSLanguage
        {
            get
            {
                if (_osLanguage == null)
                    _osLanguage = CultureInfo.CurrentCulture.Name;

                return _osLanguage;
            }
            set
            {
                _osLanguage = value;
            }
        }
    }
}