Expand and Collapse Nodes

• Jul 27, 2025
• 3 minutes to read

The TreeListView allows users to expand/collapse parent nodes to show/hide their children:

Run Demo: TreeList ViewView Example: TreeListNode - Emulate Binding to the IsExpanded property

Expand and Collapse Nodes in UI

Users can expand/collapse nodes as follows:

• Click a node’s expand button.
• Focus a node and press Ctrl + Left / Right.

Note

• If the DataViewBase.NavigationStyle property value is Row , users can press Left / Righ without Ctrl to expand/collapse nodes.
• If the TreeListView.ExpandCollapseNodesOnNavigation property value is true , users can press Left / Right without Ctrl to expand/collapse nodes regardless of the DataViewBase.NavigationStyle property value.

Expand and Collapse Nodes in Code

Use the following API to expand/collapse nodes in code:

API	Description
TreeListNodeBase.IsExpanded	Gets or sets whether the node is expanded.
TreeListView.ExpandNode / TreeListView.CollapseNode	Expands/collapses a node.
TreeListView.ChangeNodeExpanded	Gets or sets the expanded state of a node.
TreeListView.ExpandToLevel	Expands the parent nodes down to the specified nesting level.
TreeListNodeBase.ExpandAll / TreeListNodeBase.CollapseAll	Expands/collapses all child nodes within the node.
TreeListView.ExpandAllNodes / TreeListView.CollapseAllNodes	Expands/collapses all nodes within the TreeListView.
TreeListView.AutoExpandAllNodes	Gets or sets whether all nodes are automatically expanded when the TreeListView is loading.

Before a node is expanded/collapsed, the TreeListView.NodeExpanding / TreeListView.NodeCollapsing event is raised.

After a node is expanded/collapsed, the TreeListView.NodeExpanded / TreeListView.NodeCollapsed event is raised.

View Example: Load Nodes Dynamically

Expand State

Use the following properties to bind node expand states to a property:

Property	Description
TreeListView.ExpandStateBinding	Gets or sets the binding that determines which nodes are expanded.
TreeListView.ExpandStateFieldName	Gets or sets the name of the data source’s field that determines which nodes are expanded.

Note

The TreeListView.ExpandStateBinding property takes precedence over the TreeListView.ExpandStateFieldName property.

Related API

EnableDynamicLoading Property

The TreeListView in hierarchical binding mode creates child nodes dynamically when you expand their parent node.

Set the TreeListView.EnableDynamicLoading property to false to create all nodes at once when the tree is loading.

FetchSublevelChildrenOnExpand Property

The TreeListView in hierarchical binding mode fetches child nodes of sub-level nodes when you expand their parent node.

If the TreeListView.FetchSublevelChildrenOnExpand property is false , all the child nodes display expand buttons (even if they do not have children) after you expand their parent node. The expand button is hidden when you expand a sub-level node that does not contain child nodes.

The TreeListView.HasChildNodesPath property allows you to control expand buttons when sub-level children are not fetched.

ExpandNodesOnFiltering Property

Set the TreeListView.ExpandNodesOnFiltering property to true to expand a node if its child nodes contain the search text.

Tip

Topic : Filter Nodes