ASPxClientTreeView.ExpandedChanged Event
Fires on the client side after a node’s expansion state has been changed by end-user interaction.
#Declaration
ExpandedChanged: ASPxClientEvent<ASPxClientTreeViewNodeEventHandler<ASPxClientTreeView>>
#Event Data
The ExpandedChanged event's data class is ASPxClientTreeViewNodeEventArgs. The following properties provide information specific to this event:
Property | Description |
---|---|
node | Gets a node object related to the event. |
#Remarks
Write a ExpandedChanged event handler to perform specific actions on the client side each time a node’s expansion state has been changed by end-user interaction. You can use the event parameter’s ASPxClientTreeViewNodeEventArgs.node property to identify the node which has been expanded or collapsed. If a node’s expansion state has been changed programmatically, the ExpandedChanged event does not fire.
#Example
The code below demonstrates how you can define node images and change them, when expanding and collapsing nodes on the client side.
using DevExpress.Web.ASPxTreeView;
public partial class _Default : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e) {
DataBind();
DefineImages(ASPxTreeView1.Nodes);
}
protected void DefineImages(TreeViewNodeCollection nodes) {
foreach (TreeViewNode node in nodes) {
if (node.Nodes.Count > 0) {
node.Image.Url = "~/Images/closed_folder.png";
DefineImages(node.Nodes);
}
else {
node.Image.Url = "~/Images/file.png";
}
}
}
}