Utilize the Full Functionality of the Whidbey File Management - FileStream and Other Classes

13. The FileStream class supports to read, write, open and close the file management operations as well as it supports to manage the operating system file operations such as pipes, standard input and output.

14. The FileSystemEventArgs class provides data for the directory events as shown below.

Changed event handler fires the properties or security details such as size, system attributes, last write time, last access time, whenever a file is changed or updated.

Created event handler fires whenever a directory or file created in a specified path.

Deleted event handler fires whenever a file or directory is deleted from the specified path.

15. The FileSystemInfo class supports the public methods which you can use for both files and directory in the specified path, which serving as the basis for two objects such as FileInfo and DirectoryInfo, which we understand from above.

16. The FileSystemWatcher class allows to notify or fires any changes occurs in the file system or directory such as a file or directory changed, deleted or created.

Figure 1 shows the NotifyFilter properties, that you can use to watch the notifications.

 Figure 1 NotifyFilter Properties

Usage:

‘  Create a new FileSystemWatcher and its properties

Try
 Dim objFileSystemWatcher as New _ FileSystemWatcher()
 
 ‘ Watch the notification for LastAccess and LastWrite, FileName, CrationTime and the renaming of files and directories
 objFileSystemWatcher.NotifyFilter= (NotifyFilters.LastWrite Or NotifyFilters.LastAccess Or NotifyFilters.FileName Or NotifyFilters.DirectoryName Or NotifyFilters.FileName Or NotifyFilters.CreationTime)

 ‘ Only watch doc files
 objFileSystemWatcher.Filter = “*.doc”

 ‘ Add event handlers
   
      AddHandler objFileSystemWatcher.Changed, AddressOf OnChanged
     
  AddHandler objFileSystemWatcher.Created, AddressOf OnCreated
     
  AddHandler objFileSystemWatcher.Deleted, AddressOf OnChanged
      AddHandler objFileSystemWatcher.Renamed, AddressOf OnChanged
 
 ‘ Begin watching event for changed, deleted, renamed and created
 objFileSystemWatcher.EnableRaisingEvents=True
    
    ' Define the event handlers.
    Private Shared Sub OnChanged(ByVal source As Object, ByVal e As FileSystemEventArgs)
        ' Specify what is done when a file is changed, created, or deleted.
        MessageBox.Show("File: " & e.FullPath & " " & e.ChangeType)
    End Sub

    Private Shared Sub OnCreated(ByVal source As Object, ByVal e As RenamedEventArgs)
        ' Specify what is done when a file is renamed.
        MessageBox.Show("File: {0} renamed to {1}", e.OldFullPath, e.FullPath)

Catch
 MessageBox.Show(“Error in File Operation”)
End Try

Next: IOException Class and Others >>
 

More .NET Articles
More By Benoyraj Baskaran