ItemException event

The ItemException event is raised when an exception is caught during the processing of a list of FileSystemItem objects, allowing the handler to decide if the process should be aborted and the exception be thrown, if the process should continue with the next item in the list or if the same item should be retried.

Purpose

The ItemException event is used to intercept exceptions before they are thrown. This can be useful in the case where you are copying a large number of files and an error occurs on one of the files or if you are trying to access a file that is password protected. In both of these cases, custom handling of the exception can be added to the event handler, or if no special handling is required, a message could be displayed explaining the reason why the exception was thrown.

The following methods can raise the ItemException event:

Method	Description
FileSystemItem.CopyTo	Copies the item to another folder.
FileSystemItem.Delete	Permanently deletes the physical item.
FileSystemItem.MoveTo	Moves the item to another folder.
AbstractFolder.CopyFilesTo	Copies the folder's content to another folder.
AbstractFolder.GetFiles	Returns a filtered list of files contained in the folder.
AbstractFolder.GetFolders	Returns a filtered list of folders contained in the folder.
AbstractFolder.GetItems	Returns a list of items contained in the folder.
AbstractFolder.MoveFilesTo	Moves the folder's content to another folder.
AbstractFile.OpenRead	Opens the file for reading.
AbstractFile.OpenWrite	Opens the file for writing.

Basic steps - C#

To subscribe to the ItemException event, the following steps must be performed:

Create a reference to a FileSystemEvents object.

Subscribe to the ItemException event of the FileSystemEvents object using the ItemExceptionEventHandler delegate class.

Create a new method that will handle the events that are raised. For the purposes of this example, we will call the method OnItemException.

Place the desired code in the newly created event handler.

Basic steps - VB.NET

To subscribe to the ItemException event, the following steps must be performed:

Create a reference to a FileSystemEvents object using the WithEvents keyword.
Select the ItemException event from the list of available methods in the newly instantiated FileSystemEvents object. This is done in the same manner as, for example, adding the DoubleClick event of a ListBox.

You can also subscribe to the event using the AddHandler/AddressOf statement.
Place the desired code in the newly added event handler.

Demonstration

This example demonstrates how to use the ItemException event to delete a target file that already exists.

VB.NET Copy Code

VB.NET	Copy Code
`Imports Xceed.FileSystem` `Dim WithEvents fiEvents As New FileSystemEvents() Dim folder As New DiskFolder("c:\temp")` `folder.CopyFilesTo( fiEvents, Nothing, New DiskFolder( "c:\destination" ), True, False )` `Private Sub fiEvents_ItemException(ByVal sender As Object, _ ByVal e As Xceed.FileSystem.ItemExceptionEventArgs) Handles fiEvents.ItemException` `If (TypeOf e.Exception Is ItemAlreadyExistsException) Then e.TargetItem.Delete() e.Action = ItemExceptionAction.Retry End If End Sub`

Imports Xceed.FileSystem

Dim WithEvents fiEvents As New FileSystemEvents() Dim folder As New DiskFolder("c:\temp")

folder.CopyFilesTo( fiEvents, Nothing, New DiskFolder( "c:\destination" ), True, False )

Private Sub fiEvents_ItemException(ByVal sender As Object, _ ByVal e As Xceed.FileSystem.ItemExceptionEventArgs) Handles fiEvents.ItemException

If (TypeOf e.Exception Is ItemAlreadyExistsException) Then e.TargetItem.Delete() e.Action = ItemExceptionAction.Retry End If End Sub

C# Copy Code

C#	Copy Code
using Xceed.FileSystem; FileSystemEvents fiEvents = new FileSystemEvents(); fiEvents.ItemException += new ItemExceptionEventHandler( OnItemException ); DiskFolder folder = new DiskFolder( @"c:\temp" ); folder.CopyFilesTo( fiEvents, null, new DiskFolder( @"c:\destination" ), true, false ); //This method will handle the ItemException events that are raised. public static void OnItemException( object sender, ItemExceptionEventArgs e ) { if( e. Exception is ItemAlreadyExistsException ) { e.TargetItem.Delete(); e.Action = ItemExceptionAction.Retry; } } //If you no longer wish to handle the events that are raised, //you can unsubscribe from the event notifications by doing the following: fiEvents.ItemException -= new ItemExceptionEventHandler( OnItemException );

using Xceed.FileSystem;
 
FileSystemEvents fiEvents = new FileSystemEvents();
fiEvents.ItemException += new ItemExceptionEventHandler( OnItemException );
 
DiskFolder folder = new DiskFolder( @"c:\temp" );
folder.CopyFilesTo( fiEvents, null, new DiskFolder( @"c:\destination" ), true, false );
           
//This method will handle the ItemException events that are raised.
public static void OnItemException( object sender, ItemExceptionEventArgs e )
{
  if( e. Exception is ItemAlreadyExistsException )
  {
    e.TargetItem.Delete();
    e.Action = ItemExceptionAction.Retry;
  }
}
 
//If you no longer wish to handle the events that are raised,
//you can unsubscribe from the event notifications by doing the following:
 
fiEvents.ItemException -= new ItemExceptionEventHandler( OnItemException );