Xceed .NET Libraries Documentation
How to copy items from an FTP server to memory

Welcome to Xceed .NET, .NET Standard and Xamarin Libraries! > Task-Based Help > FTP capabilities > Working with classes from the Xceed.FileSystem namespace > How to copy items from an FTP server to memory

Items can be copied or moved (in other words, downloaded) from an FTP server to a folder located in memory (or any other type of folder supported by the Xceed FileSystem) using the CopyTo, CopyFilesTo, MoveTo, or MoveFilesTo methods. 

The following example demonstrates how to copy files located in a folder on an FTP server to a folder located in memory using the steps listed below:

  1. Create an instance of the FtpConnection class to establish a connection between the client and the FTP server. If you are using FtpConnection in a UI application, assign your form (or any other control that implements the ISynchronizeInvoke interface) to the SynchronizingObject property and call Application.DoEvents in an event such as ByteProgression; see the Events section below for an example of this.

  2. Create an instance of an FtpFolder which will represent the folder on the FTP server from which to retrieve the files. If a folder name is not specified, the folder will represent the current working folder. 

  3. Create an instance of a MemoryFolder which will representing the folder, in memory, where the files will be downloaded to. Any other implementation of the AbstractFolder class, such as the DiskFolder class which represents a folder located on a local drive, can also be used as the destination folder. 

  4. Call the FtpFolder's CopyFilesTo method to copy the folder and its content from the FTP server to memory. 

  5. Dispose of the FtpConnection once the file transfer is completed by calling its Dispose method or, in C#, by creating the FtpConnection instance in a using block. If an instance of an FtpConnection object is not disposed of, connections with the FTP server may remain active until the FTP server times-out or the garbage-collector passes.  

VB.NET Copy Code

Imports Xceed.FileSystem
Imports Xceed.Ftp

Dim connection As FtpConnection

Try
  connection = New FtpConnection( "ftp.server.com" )

Dim source As New FtpFolder(connection, "test")
Dim destination As New MemoryFolder("RAM", "temp_files")

  source.CopyFilesTo( destination, True, True )

Dim file As AbstractFile
For Each file In destination.GetFiles( True )
  System.Diagnostics.Debug.WriteLine( file.Name )
Next file

Finally
  connection.Dispose()
End Try

C# Copy Code
using Xceed.FileSystem;
using Xceed.Ftp;
 
using( FtpConnection connection = new FtpConnection( "ftp.server.com" ) )
{
  FtpFolder source = new FtpFolder( connection, "test" );        
  MemoryFolder destination = new MemoryFolder( "RAM", "temp_files" );
 
  source.CopyFilesTo( destination, true, true );
 
  foreach( AbstractFile file in destination.GetFiles( true ) )
  {
    System.Diagnostics.Debug.WriteLine( file.Name );
  }
}

Events

All methods exposed by the Xceed FileSystem's FileSystemItem, AbstractFolder, AbstractFile, and derived classes have an overload that can be used when events are required. 

If you are using FtpConnection in a UI application, assign your form (or any other control that implements the ISynchronizeInvoke interface) to the SynchronizingObject property and call Application.DoEvents in an event such as ByteProgression.

With the exception of the FtpConnection's ParsingListingLine event, events can be handled by creating an instance of the FileSystemEvents class and subscribing to the desired events. For example:

VB.NET Copy Code

Imports Xceed.FileSystem
Imports Xceed.Ftp

Dim connection As FtpConnection
Dim events As FileSystemEvents

Try
  connection = New FtpConnection( "ftp.server.com" )
  'When using FtpConnection in a UI application
  connection.SynchronizingObject = Me

  events = New FileSystemEvents()
  AddHandler events.ItemProgression, AddressOf Me.item_progression
  AddHandler events.ByteProgression, AddressOf Me.byte_progression

  Dim source As New FtpFolder(connection, "test")
  Dim destination As New MemoryFolder("RAM", "temp_files")

  source.CopyFilesTo( events, Nothing, destination, True, True )

  Dim file As AbstractFile
  For Each file In destination.GetFiles( True )
    System.Diagnostics.Debug.WriteLine( file.Name )
  Next file

Finally
  connection.Dispose()
  RemoveHandler events.ItemProgression, AddressOf Me.item_progression
  RemoveHandler events.ItemProgression, AddressOf Me.byte_progression
End Try

Private Sub item_progression(ByVal sender As Object, ByVal e As ItemProgressionEventArgs)
  System.Diagnostics.Debug.WriteLine(e.CurrentItem.Name)
End Sub

Private Sub byte_progression( ByVal sender As Object, ByVal e As ByteProgressionEventArgs )
  Application.DoEvents()
End Sub

C# Copy Code

using Xceed.FileSystem;
using Xceed.Ftp;

FileSystemEvents events = new FileSystemEvents();
events.ItemProgression += new ItemProgressionEventHandler( this.item_progression );
events.ByteProgression += new ByteProgressionEventHandler( this.byte_progression );

using( FtpConnection connection = new FtpConnection( "ftp.server.com" ) )
{
  //When using FtpConnection in a UI application
  connection.SynchronizingObject = this;

  FtpFolder source = new FtpFolder( connection, "test" );        
  MemoryFolder destination = new MemoryFolder( "RAM", "temp_files" );

  source.CopyFilesTo( events, null, destination, true, true );

  foreach( AbstractFile file in destination.GetFiles( true ) )
  {
    System.Diagnostics.Debug.WriteLine( file.Name );
  }
}

events.ItemProgression -= new ItemProgressionEventHandler( this.item_progression );
events.ByteProgression -= new ByteProgressionEventHandler( this.byte_progression );

private void item_progression( object sender, ItemProgressionEventArgs e )
{
  System.Diagnostics.Debug.WriteLine( e.CurrentItem.Name );
}

private void byte_progression( object sender, ByteProgressionEventArgs e )
{
  Application.DoEvents();
}

Things to consider

  • Do you want the FTP server to initiate the data connection rather than the client-side? Set the FtpConnection's PassiveTransfer property to false. 

  • Do you want to decrease or increase the period of time after which an FTP operation should timeout? Change the value of the FtpConnection's   Timeout property. 

  • Do you want to create a log file of the FTP process? Set the FtpConnection's TraceWriter property. 

  • Do you want to filter (specify specific files and folders) the items that are to be copied? Use filters. 

  • Do you want to display progress information? Create an instance of the FileSystemEvents class and handle the ByteProgression and/or ItemProgression events. 

  • Do you want to display progress information when a folder is being scanned? Create an instance of the FileSystemEvents class and handle the ScanningFolder event. 

  • Do you want to intervene when an error occurs with one or more of the items being manipulated? Create an instance of the FileSystemEvents class and handle the ItemException event. 

  • Do you want to prevent routers from prematurely closing the command channel while a long data transfer is taking place. Set the KeepAliveInterval property. 

  • Do you want quick and easy access to FTP functionalities in the same style as the ActiveX version of the Xceed FTP Library? Use the FtpClient class instead. (Note: The AsyncFtpClient should now be considered obsolete. Instead, use the FtpClient class, assigning a value to its SynchronizingObject property.)

 

 

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