Version

ShowExpansionIndicator Property

Gets/sets a value indicating whether expansion indicators (plus-sign (+) and minus-sign (-) buttons are displayed next to tree nodes that contain child tree nodes.
Syntax
'Declaration
 
Public Property ShowExpansionIndicator As ShowExpansionIndicator
public ShowExpansionIndicator ShowExpansionIndicator {get; set;}
Remarks

This property determines when a node will display an expansion indicator.

When set to the Default or CheckOnLoad, nodes will automatically determine whether an expansion indicator is necessary based on whether or not there are child nodes.

To load nodes "on demand", use the CheckOnExpand setting. With this setting, the node will show an expansion indicator until the first time it is expanded. At that time, the UltraTree.BeforeExpand event will fire. If the event completes successfully and is not cancelled, then the node will determine if any child nodes were added. If child nodes were added, the node will expand normally and show an expansion indicator. If no children were added, the expansion indicator will disappear and the node will not expand.

To restore the expansion indicator of a node once it has disappeared, use the UltraTree.ResetExpansionIndicator method of the UltraTree.

When loading nodes on demand, it is generally recommended to also set NodeDoubleClickAction to ToggleExpansionWhenExpansionIndicatorVisible.

Example
The following sample code illustrates how to specify the style of nodes.

Imports Infragistics.Win
Imports Infragistics.Win.UltraWinTree

Private Sub button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button8.Click

    ' Note: the Override objects are exposed as properties off
    ' the tree, the node and the nodes collection as well as
    ' items in the NodeLevelOverrides collection. This allows
    ' default settings to be specified for the tree, a node, 
    ' a node's children or for a level in the tree.

    ' Use the tree's Override property to
    ' set the default for all nodes.
    Me.ultraTree1.Override.NodeStyle = NodeStyle.CheckBox
    Me.ultraTree1.Override.ShowExpansionIndicator = ShowExpansionIndicator.CheckOnDisplay
    Me.ultraTree1.Override.TipStyleNode = TipStyleNode.Show
    ' Resrve space for checkboxes even if the node is't that style
    Me.ultraTree1.Override.ReserveCheckBoxSpace = DefaultableBoolean.True

    ' Set the default for nodes that are at level 2 
    ' (i.e. grandchild nodes of root modes).
    ' This overrides the default setting above.
    Me.ultraTree1.NodeLevelOverrides(2).NodeStyle = NodeStyle.Standard
    Me.ultraTree1.NodeLevelOverrides(2).TipStyleNode = TipStyleNode.Hide
    Me.ultraTree1.NodeLevelOverrides(2).ShowExpansionIndicator = ShowExpansionIndicator.CheckOnExpand

    ' Set the default for nodes at the root level. 
    ' This overrides the default settings above.
    Me.ultraTree1.Nodes.Override.NodeStyle = NodeStyle.CheckBoxTriState

    Dim node As UltraTreeNode

    ' Get a specific node by its key value. 
    ' Note: this will return the node that has that key
    ' from anywhere in the tree structure since keys are
    ' unique across the entire tree.
    node = Me.ultraTree1.GetNodeByKey("child node 1")

    ' Set the property for that specific node only.
    ' This overrides any default settings above.
    node.Override.NodeStyle = NodeStyle.Standard

    ' Set the property for that specific node's child nodes
    node.Nodes.Override.NodeStyle = NodeStyle.OptionButton

End Sub
using Infragistics.Win;
using Infragistics.Win.UltraWinTree;

private void button8_Click(object sender, System.EventArgs e)
{

	// Note: the Override objects are exposed as properties off
	// the tree, the node and the nodes collection as well as
	// items in the NodeLevelOverrides collection. This allows
	// default settings to be specified for the tree, a node, 
	// a node's children or for a level in the tree.

	// Use the tree's Override property to
	// set the default for all nodes.
	this.ultraTree1.Override.NodeStyle = NodeStyle.CheckBox;
	this.ultraTree1.Override.ShowExpansionIndicator = ShowExpansionIndicator.CheckOnDisplay;
	this.ultraTree1.Override.TipStyleNode = TipStyleNode.Show;
	// Resrve space for checkboxes even if the node is't that style
	this.ultraTree1.Override.ReserveCheckBoxSpace = DefaultableBoolean.True;
		
	// Set the default for nodes that are at level 2 
	// (i.e. grandchild nodes of root modes).
	// This overrides the default setting above.
	this.ultraTree1.NodeLevelOverrides[2].NodeStyle = NodeStyle.Standard;
	this.ultraTree1.NodeLevelOverrides[2].TipStyleNode = TipStyleNode.Hide;
	this.ultraTree1.NodeLevelOverrides[2].ShowExpansionIndicator = ShowExpansionIndicator.CheckOnExpand;

	// Set the default for nodes at the root level. 
	// This overrides the default settings above.
	this.ultraTree1.Nodes.Override.NodeStyle = NodeStyle.CheckBoxTriState;

	// Get a specific node by its key value. 
	// Note: this will return the node that has that key
	// from anywhere in the tree structure since keys are
	// unique across the entire tree.
	UltraTreeNode node = this.ultraTree1.GetNodeByKey("child node 1");

	// Set the property for that specific node only.
	// This overrides any default settings above.
	node.Override.NodeStyle = NodeStyle.Standard;

	// Set the property for that specific node's child nodes
	node.Nodes.Override.NodeStyle = NodeStyle.OptionButton;
		
}
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also