Namespace:
System.IO
Assembly:
System (in System.dll)
Visual Basic (Declaration)
Public Class FileSystemEventArgs _
Inherits EventArgs
Dim instance As FileSystemEventArgs
public class FileSystemEventArgs : EventArgs
public ref class FileSystemEventArgs : public EventArgs
public class FileSystemEventArgs extends EventArgs
The FileSystemEventArgs class is passed as a parameter to event handlers for these events:
The Changed event occurs when changes are made to the size, system attributes, last write time, last access time, or security permissions in a file or directory in the specified Path of a FileSystemWatcher.
The Created event occurs when a file or directory in the specified Path of a FileSystemWatcher is created.
The Deleted event occurs when a file or directory in the specified Path of a FileSystemWatcher is deleted. For more information, see FileSystemWatcher.
The following example shows how to create a FileSystemWatcher to monitor file changes (creates, deletes, renames, changes) occurring on a disk drive. The example also shows how to properly receive error notifications.
Imports System.IO
Module Module1
Sub Main()
' Create a FileSystemWatcher to monitor all files on drive C.
Dim fsw As New FileSystemWatcher("C:\")
' Watch for changes in LastAccess and LastWrite times, and
' the renaming of files or directories.
fsw.NotifyFilter = (NotifyFilters.LastAccess Or NotifyFilters.LastWrite _
Or NotifyFilters.FileName Or NotifyFilters.DirectoryName)
' Register a handler that gets called when a
' file is created, changed, or deleted.
AddHandler fsw.Changed, New FileSystemEventHandler(AddressOf OnChanged)
' The commented line of code below is a shorthand of the above line.
' AddHandler fsw.Changed, AddressOf OnChanged
' NOTE: The shorthand version is used in the remainder of this code.
' FileSystemEventHandler
AddHandler fsw.Created, AddressOf OnChanged
' FileSystemEventHandler
AddHandler fsw.Deleted, AddressOf OnChanged
' Register a handler that gets called when a file is renamed.
' RenamedEventHandler
AddHandler fsw.Renamed, AddressOf OnRenamed
' Register a handler that gets called if the
' FileSystemWatcher needs to report an error.
' ErrorEventHandler
AddHandler fsw.Error, AddressOf OnError
' Begin watching.
fsw.EnableRaisingEvents = True
' Wait for the user to quit the program.
Console.WriteLine("Press 'Enter' to quit the sample.")
Console.ReadLine()
End Sub
' This method is called when a file is created, changed, or deleted.
Private Sub OnChanged(ByVal source As Object, ByVal e As FileSystemEventArgs)
' Show that a file has been created, changed, or deleted.
Dim wct As WatcherChangeTypes = e.ChangeType
Console.WriteLine("File {0} {1}", e.FullPath, wct.ToString())
End Sub
' This method is called when a file is renamed.
Private Sub OnRenamed(ByVal source As Object, ByVal e As RenamedEventArgs)
' Show that a file has been renamed.
Dim wct As WatcherChangeTypes = e.ChangeType
Console.WriteLine("File {0} {2} to {1}", e.OldFullPath, e.FullPath, wct.ToString())
End Sub
' This method is called when the FileSystemWatcher detects an error.
Private Sub OnError(ByVal source As Object, ByVal e As ErrorEventArgs)
' 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 TypeOf e.GetException Is InternalBufferOverflowException Then
' 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)
End If
End Sub
End Module
using System;
using System.IO;
class Program
{
static void Main(string[] args)
{
// Create a FileSystemWatcher to monitor all files on drive C.
FileSystemWatcher fsw = new FileSystemWatcher("C:\\");
// Watch for changes in LastAccess and LastWrite times, and
// the renaming of files or directories.
fsw.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite
| NotifyFilters.FileName |NotifyFilters.DirectoryName;
// Register a handler that gets called when a
// file is created, changed, or deleted.
fsw.Changed += new FileSystemEventHandler(OnChanged);
fsw.Created += new FileSystemEventHandler(OnChanged);
fsw.Deleted += new FileSystemEventHandler(OnChanged);
// Register a handler that gets called when a file is renamed.
fsw.Renamed += new RenamedEventHandler(OnRenamed);
// Register a handler that gets called if the
// FileSystemWatcher needs to report an error.
fsw.Error += new ErrorEventHandler(OnError);
// Begin watching.
fsw.EnableRaisingEvents = true;
Console.WriteLine("Press \'Enter\' to quit the sample.");
Console.ReadLine();
}
// This method is called when a file is created, changed, or deleted.
private static void OnChanged(object source, FileSystemEventArgs e)
{
// Show that a file has been created, changed, or deleted.
WatcherChangeTypes wct = e.ChangeType;
Console.WriteLine("File {0} {1}", e.FullPath, wct.ToString());
}
// This method is called when a file is renamed.
private static void OnRenamed(object source, RenamedEventArgs e)
{
// Show that a file has been 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)
{
// 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));
}
}
}
System..::.Object
System..::.EventArgs
System.IO..::.FileSystemEventArgs
System.IO..::.RenamedEventArgs
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
Reference