TreeView.SelectedNode Property
Assembly: System.Web (in System.Web.dll)
The text of a node in the TreeView control can be in one of two modes: selection mode and navigation mode. By default, a node is in selection mode. To put a node into navigation mode, set the NavigateUrl property for the node to a value other than an empty string (""). To put a node into selection mode, set the NavigateUrl property for the node to empty string ("").
When a node is in selection mode, the user can select a node by clicking on the text in the node. Use the SelectedNode property to determine which node is selected in the TreeView control.
Note |
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A node cannot be selected when the TreeView control displays hyperlinks. When hyperlinks are displayed, the SelectedNode property always returns null. |
When the user selects a different node in the TreeView control by clicking the text in the new node, the SelectedNodeChanged event is raised, by default. You can specify a different event by setting the SelectAction property for the property. The following table lists the available options.
Selection action | Description |
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Toggles the node between expanded and collapsed. Raises the TreeNodeExpanded or TreeNodeCollapsed event, as appropriate. | |
Raises no events when a node is selected. | |
Raises the SelectedNodeChanged event when a node is selected. | |
Raises both the SelectedNodeChanged and TreeNodeExpanded events when a node is selected. Nodes are only expanded, never collapsed. |
Note |
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The HoverNodeStyle is not rendered for a node with its SelectAction property set to TreeNodeSelectAction.None. |
The following code example demonstrates how to use the SelectedNode property to determine the value of the selected 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 Select_Change(Object sender, EventArgs e) { Message.Text = "You selected: " + LinksTreeView.SelectedNode.Text; } </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>TreeView SelectedNodeStyle Example</title> </head> <body> <form id="form1" runat="server"> <h3>TreeView SelectedNodeStyle Example</h3> <asp:TreeView id="LinksTreeView" Font-Names= "Arial" ForeColor="Blue" SelectedNodeStyle-ForeColor="Green" SelectedNodeStyle-VerticalPadding="0" OnSelectedNodeChanged="Select_Change" runat="server"> <LevelStyles> <asp:TreeNodeStyle ChildNodesPadding="10" Font-Bold="true" Font-Size="12pt" ForeColor="DarkGreen"/> <asp:TreeNodeStyle ChildNodesPadding="5" Font-Bold="true" Font-Size="10pt"/> <asp:TreeNodeStyle ChildNodesPadding="5" Font-UnderLine="true" Font-Size="10pt"/> <asp:TreeNodeStyle ChildNodesPadding="10" Font-Size="8pt"/> </LevelStyles> <Nodes> <asp:TreeNode Text="Table of Contents" SelectAction="None"> <asp:TreeNode Text="Chapter One"> <asp:TreeNode Text="Section 1.0"> <asp:TreeNode Text="Topic 1.0.1"/> <asp:TreeNode Text="Topic 1.0.2"/> <asp:TreeNode Text="Topic 1.0.3"/> </asp:TreeNode> <asp:TreeNode Text="Section 1.1"> <asp:TreeNode Text="Topic 1.1.1"/> <asp:TreeNode Text="Topic 1.1.2"/> <asp:TreeNode Text="Topic 1.1.3"/> <asp:TreeNode Text="Topic 1.1.4"/> </asp:TreeNode> </asp:TreeNode> <asp:TreeNode Text="Chapter Two"> <asp:TreeNode Text="Section 2.0"> <asp:TreeNode Text="Topic 2.0.1"/> <asp:TreeNode Text="Topic 2.0.2"/> </asp:TreeNode> </asp:TreeNode> </asp:TreeNode> <asp:TreeNode Text="Appendix A" /> <asp:TreeNode Text="Appendix B" /> <asp:TreeNode Text="Appendix C" /> </Nodes> </asp:TreeView> <br /><br /> <asp:Label id="Message" runat="server"/> </form> </body> </html>
Available since 2.0
