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FileSystemEventArgs Class

Provides data for the directory events: Changed, Created, Deleted.

System.Object
  System.EventArgs
    System.IO.FileSystemEventArgs
      System.IO.RenamedEventArgs

Namespace:  System.IO
Assembly:  System (in System.dll)

'Declaration
Public Class FileSystemEventArgs _
	Inherits EventArgs

The FileSystemEventArgs type exposes the following members.

  NameDescription
Public methodFileSystemEventArgsInitializes a new instance of the FileSystemEventArgs class.
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  NameDescription
Public propertyChangeTypeGets the type of directory event that occurred.
Public propertyFullPathGets the fully qualifed path of the affected file or directory.
Public propertyNameGets the name of the affected file or directory.
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  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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