Provides methods for trapping events that occur to items. This class is never instantiated.
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
Available in Sandboxed Solutions: Yes
Available in SharePoint Online
This class is not instantiated but the item event receiver class of a custom event handler must derive from this class and override its methods for the event types that are handled.
If an item is moved, it is treated in the same way as an item that has been removed and then added.
Before and After properties are guaranteed for post events on documents, but Before properties are not available for post events on list items.
The following code example uses this class to add an item to a specified Announcements list whenever an attachment is added to a list.
Imports System Imports Microsoft.SharePoint Namespace Example_Namespace Public Class Class_Name Inherits SPItemEventReceiver Public Overrides Sub ItemAttachmentAdded(ByVal properties As SPItemEventProperties) Using oSiteCollectionEvent As New SPSite(properties.SiteId) Dim oSiteEvent As SPWeb = oSiteCollectionEvent.OpenWeb(properties.RelativeWebUrl) Dim oItemsEvent As SPListItemCollection = oSiteEvent.Lists(properties.ListTitle).Items End Using Using oSiteCollection As New SPSite("http://Top_Site") Dim oWebsite As SPWeb = oSiteCollection.OpenWeb("Website_Name") Dim oList As SPList = oWebsite.Lists("Announcements") Dim collListItems As SPListItemCollection = oList.Items Dim oItem As SPListItem = collListItems.Add() oItem("Title") = properties.UserDisplayName & " added an attachment to " & oItemsEvent(properties.ListItemId).Title & " in list " & properties.ListTitle & " at " & properties.WebUrl oItem.Update() End Using End Sub End Class End Namespace
Certain objects implement the IDisposable interface, and you must avoid retaining these objects in memory after they are no longer needed. For information about good coding practices, see Disposing Objects.