TreeListView.ShowingNodeFooter Event

Fires for each parent node before showing its node footer.

Namespace: DevExpress.Xpf.Grid

Assembly: DevExpress.Xpf.Grid.v24.2.dll

NuGet Package: DevExpress.Wpf.Grid.Core

Declaration

C#

public event TreeListShowingNodeFooterEventHandler ShowingNodeFooter

VB.NET

Public Event ShowingNodeFooter As TreeListShowingNodeFooterEventHandler

Event Data

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

Property	Description
Allow	Gets or sets whether the operation is allowed. Inherited from TreeListNodeAllowEventArgs.
Handled	Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs.
IsRootNode	Gets whether the processed node is a root node.
Node	Gets the processed node. Inherited from TreeListNodeEventArgs.
OriginalSource	Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs.
RoutedEvent	Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs.
Row	Gets the processed row. Inherited from TreeListNodeEventArgs.
Source	Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.

The event data class exposes the following methods:

Method	Description
InvokeEventHandler(Delegate, Object)	When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation. Inherited from RoutedEventArgs.
OnSetSource(Object)	When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. Inherited from RoutedEventArgs.

Remarks

Handle this event to prevent the TreeListView from displaying any node footers.

The code sample below demonstrates how to prevent showing node footers for those nodes that have a single child.

C#

private void OnShowingNodeFooter(object sender, DevExpress.Xpf.Grid.TreeList.TreeListShowingNodeFooterEventArgs e) {
    if(e.IsRootNode || e.Node.Nodes.Count(node => node.IsVisible) == 1)
        e.Allow = false;
}

XAML

<dxg:TreeListControl ItemsSource="{Binding Path=SpaceObjects}">
    <dxg:TreeListControl.Columns>
        <dxg:TreeListColumn FieldName="Name" Header="Name" Width="*" />
        <dxg:TreeListColumn FieldName="MeanRadiusInKM" Header="Mean radius (km)" Width="*" />
        <dxg:TreeListColumn FieldName="Mass10pow21kg" Header="Mass (10&#x00B2;&#x00B9;kg)" Width="*"/>
    </dxg:TreeListControl.Columns>
    <dxg:TreeListControl.View>
        <dxg:TreeListView  
        KeyFieldName="ObjectId" 
        ParentFieldName="ParentId" 
        ShowNodeFooters="True" 
        TotalSummaryPosition="Bottom" 
        ShowingNodeFooter="OnShowingNodeFooter"> 
            <dxg:TreeListView.NodeSummary>
                <dxg:TreeListSummaryItem FieldName="MeanRadiusInKM" SummaryType="Max" />
                <dxg:TreeListSummaryItem FieldName="MeanRadiusInKM" SummaryType="Min" />
            </dxg:TreeListView.NodeSummary>
        </dxg:TreeListView>
    </dxg:TreeListControl.View>
</dxg:TreeListControl>