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DxTreeView.SetNodeExpanded(Func<ITreeViewNodeInfo, Boolean>, Boolean) Method

Expands or collapses the specified node.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

#Declaration

C#
public void SetNodeExpanded(
    Func<ITreeViewNodeInfo, bool> predicate,
    bool expanded
)

#Parameters

Name Type Description
predicate Func<ITreeViewNodeInfo, Boolean>

A method delegate that specifies a particular node.

expanded Boolean

true, to expand a node; false, to collapse a node.

#Remarks

Use the SetNodeExpanded method to expand or collapse a node programmatically.

The following code snippet expands a selected node if it has children.

Razor
<DxTreeView @ref="@SampleTreeView" 
            AllowSelectNodes="true"
            SelectionChanged="@SelectionChanged">
    @* ... *@
</DxTreeView>

@code  {
    DxTreeView SampleTreeView;
    protected void SelectionChanged(TreeViewNodeEventArgs e) {
        SampleTreeView.CollapseAll();
        SampleTreeView.ExpandToNode((n) => n.Text == e.NodeInfo.Text);
        if (!SampleTreeView.GetSelectedNodeInfo().IsLeaf) {
            SampleTreeView.SetNodeExpanded((n) => n.Text == e.NodeInfo.Text, true);
        }    
    }
}

Note

This method does not expand/collapse the specified node if Load Child Nodes on Demand mode is enabled, and the node is not loaded yet.

See Also