Gets or sets the type of changes to watch for.
Namespace:
System.IO
Assembly:
System (in System.dll)
Visual Basic (Declaration)
<IODescriptionAttribute("FSW_ChangedFilter")> _
Public Property NotifyFilter As NotifyFilters
Dim instance As FileSystemWatcher
Dim value As NotifyFilters
value = instance.NotifyFilter
instance.NotifyFilter = value
[IODescriptionAttribute("FSW_ChangedFilter")]
public NotifyFilters NotifyFilter { get; set; }
[IODescriptionAttribute(L"FSW_ChangedFilter")]
public:
property NotifyFilters NotifyFilter {
NotifyFilters get ();
void set (NotifyFilters value);
}
public function get NotifyFilter () : NotifyFilters
public function set NotifyFilter (value : NotifyFilters)
You can combine the members of the NotifyFilters enumeration to watch for more than one type of change at a time. For example, you can watch for changes in size of a file, and for changes in the LastWrite time. This raises an event anytime there is a change in file or folder size, or a change in the LastWrite time of the file or folder.
This is one way to filter out unwanted notifications. For more information on filtering out unwanted notifications, see the Filter, IncludeSubdirectories, and InternalBufferSize properties.
The following example creates a FileSystemWatcher to watch the directory specified at run time. The component is set to watch for changes in LastWrite and LastAccess time, the creation, deletion, or renaming of text files in the directory. If a file is changed, created, or deleted, the path to the file prints to the console. When a file is renamed, the old and new paths print to the console.
Use the System.Diagnostics and System.IO namespaces for this example.
Public Class Watcher
Public Shared Sub Main()
Run()
End Sub
<PermissionSet(SecurityAction.Demand, Name:="FullTrust")> _
Private Shared Sub Run
Dim args() As String = System.Environment.GetCommandLineArgs()
' If a directory is not specified, exit the program.
If args.Length <> 2 Then
' Display the proper way to call the program.
Console.WriteLine("Usage: Watcher.exe (directory)")
Return
End If
' Create a new FileSystemWatcher and set its properties.
Dim watcher As New FileSystemWatcher()
watcher.Path = args(1)
' Watch for changes in LastAccess and LastWrite times, and
' the renaming of files or directories.
watcher.NotifyFilter = (NotifyFilters.LastAccess Or NotifyFilters.LastWrite Or NotifyFilters.FileName Or NotifyFilters.DirectoryName)
' Only watch text files.
watcher.Filter = "*.txt"
' Add event handlers.
AddHandler watcher.Changed, AddressOf OnChanged
AddHandler watcher.Created, AddressOf OnChanged
AddHandler watcher.Deleted, AddressOf OnChanged
AddHandler watcher.Renamed, AddressOf OnRenamed
' Begin watching.
watcher.EnableRaisingEvents = True
' Wait for the user to quit the program.
Console.WriteLine("Press 'q' to quit the sample.")
While Chr(Console.Read()) <> "q"c
End While
End Sub
' Define the event handlers.
Private Shared Sub OnChanged(source As Object, e As FileSystemEventArgs)
' Specify what is done when a file is changed, created, or deleted.
Console.WriteLine("File: " & e.FullPath & " " & e.ChangeType)
End Sub
Private Shared Sub OnRenamed(source As Object, e As RenamedEventArgs)
' Specify what is done when a file is renamed.
Console.WriteLine("File: {0} renamed to {1}", e.OldFullPath, e.FullPath)
End Sub
End Class
public class Watcher
{
public static void Main()
{
Run();
}
[PermissionSet(SecurityAction.Demand, Name="FullTrust")]
public static void Run()
{
string[] args = System.Environment.GetCommandLineArgs();
// If a directory is not specified, exit program.
if(args.Length != 2)
{
// Display the proper way to call the program.
Console.WriteLine("Usage: Watcher.exe (directory)");
return;
}
// Create a new FileSystemWatcher and set its properties.
FileSystemWatcher watcher = new FileSystemWatcher();
watcher.Path = args[1];
/* 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);
// Begin watching.
watcher.EnableRaisingEvents = true;
// Wait for the user to quit the program.
Console.WriteLine("Press \'q\' to quit the sample.");
while(Console.Read()!='q');
}
// 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);
}
private static void OnRenamed(object source, RenamedEventArgs e)
{
// Specify what is done when a file is renamed.
Console.WriteLine("File: {0} renamed to {1}", e.OldFullPath, e.FullPath);
}
}
public ref class Watcher
{
private:
// Define the event handlers.
static void OnChanged( Object^ /*source*/, FileSystemEventArgs^ e )
{
// Specify what is done when a file is changed, created, or deleted.
Console::WriteLine( "File: {0} {1}", e->FullPath, e->ChangeType );
}
static void OnRenamed( Object^ /*source*/, RenamedEventArgs^ e )
{
// Specify what is done when a file is renamed.
Console::WriteLine( "File: {0} renamed to {1}", e->OldFullPath, e->FullPath );
}
public:
[PermissionSet(SecurityAction::Demand, Name="FullTrust")]
int static run()
{
array<String^>^args = System::Environment::GetCommandLineArgs();
// If a directory is not specified, exit program.
if ( args->Length != 2 )
{
// Display the proper way to call the program.
Console::WriteLine( "Usage: Watcher.exe (directory)" );
return 0;
}
// Create a new FileSystemWatcher and set its properties.
FileSystemWatcher^ watcher = gcnew FileSystemWatcher;
watcher->Path = args[ 1 ];
/* Watch for changes in LastAccess and LastWrite times, and
the renaming of files or directories. */
watcher->NotifyFilter = static_cast<NotifyFilters>(NotifyFilters::LastAccess |
NotifyFilters::LastWrite | NotifyFilters::FileName | NotifyFilters::DirectoryName);
// Only watch text files.
watcher->Filter = "*.txt";
// Add event handlers.
watcher->Changed += gcnew FileSystemEventHandler( Watcher::OnChanged );
watcher->Created += gcnew FileSystemEventHandler( Watcher::OnChanged );
watcher->Deleted += gcnew FileSystemEventHandler( Watcher::OnChanged );
watcher->Renamed += gcnew RenamedEventHandler( Watcher::OnRenamed );
// Begin watching.
watcher->EnableRaisingEvents = true;
// Wait for the user to quit the program.
Console::WriteLine( "Press \'q\' to quit the sample." );
while ( Console::Read() != 'q' )
;
}
};
int main() {
Watcher::run();
}
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