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

Expands or collapses the specified node.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.2.dll

NuGet Package: DevExpress.Blazor

Declaration

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 code sample below demonstrates how to expand a selected node if it has children.

<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.