XPBaseCollection.ListChanged Event

Occurs when the list or an item in the list of the XPBaseCollection collection is changed.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v25.2.dll

NuGet Package: DevExpress.Xpo

Declaration

C#

public event ListChangedEventHandler ListChanged

VB.NET

Public Event ListChanged As ListChangedEventHandler

Event Data

The ListChanged event's data class is ListChangedEventArgs. The following properties provide information specific to this event:

Property	Description
ListChangedType	Gets the type of change.
NewIndex	Gets the index of the item affected by the change.
OldIndex	Gets the old index of an item that has been moved.
PropertyDescriptor	Gets the PropertyDescriptor that was added, changed, or deleted.

Remarks

To subscribe to this event, override the XPBaseObject.CreateCollection<T> or PersistentBase.CreateCollection method of your persistent class.

C#

// Example for generic collection:
protected override XPCollection<T> CreateCollection<T>(XPMemberInfo property) {
    XPCollection<T> collection = base.CreateCollection<T>(property);
    if (property.Name == "MyGenericCollectionProperty") {
        collection.ListChanged += collection_ListChanged;
    }
    return collection;
}
// Example for non-generic collection:
protected override XPCollection CreateCollection(XPMemberInfo property) {
    XPCollection collection = base.CreateCollection(property);
    if (property.Name == "MyCollectionProperty") {
        collection.ListChanged += collection_ListChanged;
    }
    return collection;
}

VB.NET

' Example for generic collection:
Protected Overrides Function CreateCollection(Of T)(ByVal [property] As XPMemberInfo) As XPCollection(Of T)
    Dim collection As XPCollection(Of T) = MyBase.CreateCollection(Of T)([property])
    If [property].Name = "MyGenericCollectionProperty" Then
        AddHandler collection.ListChanged, AddressOf collection_ListChanged
    End If
    Return collection
End Function
' Example for non-generic collection:
Protected Overrides Function CreateCollection(ByVal [property] As XPMemberInfo) As XPCollection
    Dim collection As XPCollection = MyBase.CreateCollection([property])
    If [property].Name = "MyCollectionProperty" Then
        AddHandler collection.ListChanged, AddressOf collection_ListChanged
    End If
    Return collection
End Function

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the ListChanged event.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

xaf-how-to-create-custom-event-and-resource-classes-for-scheduler/CS/XPO/CustomEventsAndResources.Module/BusinessObjects/CustomEventWithUserResources.cs#L107

    : base(session) {
    Resources.ListChanged += new ListChangedEventHandler(Resources_ListChanged);
}