TreeView.TreeNodeCollapsed Event
.NET Framework (current version)
Occurs when a node is collapsed in the TreeView control.
Assembly: System.Web (in System.Web.dll)
The TreeNodeCollapsed event is raised when a node is collapsed in the TreeView control. This allows you to provide an event-handling method that performs a custom routine whenever this event occurs.
For more information about handling events, see NIB: Consuming Events.
The following code example demonstrates how to use the TreeNodeCollapsed event to update the content of a Label control when the user collapses a node in the TreeView control.
<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> void Node_Expand(Object sender, TreeNodeEventArgs e) { Message.Text = "You expanded the " + e.Node.Text + " node."; } void Node_Collapse(Object sender, TreeNodeEventArgs e) { Message.Text = "You collapsed the " + e.Node.Text + " node."; } </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>TreeView TreeNodeExpand and TreeNodeCollapse Example</title> </head> <body> <form id="form1" runat="server"> <h3>TreeView TreeNodeExpand and TreeNodeCollapse Example</h3> <asp:TreeView id="BookTreeView" ExpandDepth="1" OnTreeNodeExpanded="Node_Expand" OnTreeNodeCollapsed="Node_Collapse" runat="server"> <Nodes> <asp:TreeNode Value="Chapter 1" Text="Chapter 1"> <asp:TreeNode Value="Section 1" Text="Section 1"> <asp:TreeNode Value="Paragraph 1" Text="Paragraph 1"> </asp:TreeNode> </asp:TreeNode> <asp:TreeNode Value="Section 2" Text="Section 2"> </asp:TreeNode> </asp:TreeNode> </Nodes> </asp:TreeView> <br /> <asp:Label id="Message" runat="server"/> </form> </body> </html>
.NET Framework
Available since 2.0
Available since 2.0
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