TreeNode.ToggleExpandState Method ()

 

Alternates between the expanded and collapsed state of the node.

Namespace:   System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

Public Sub ToggleExpandState

Use the ToggleExpandState method to alternate between an expanded and a collapsed state for the node. For example, if the node is collapsed, calling the ToggleExpandState method expands the node, and vice versa.

System_CAPS_noteNote

As an alternative, you can set the Expanded property directly.

The following code example demonstrates how to use the ToggleExpandState method to alternate between an expanded and a collapsed state for the root node of a TreeView control.


<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub Check_Changed(ByVal sender As Object, ByVal e As EventArgs)

    ' Alternate the state of the root node. The root node
    ' is the first element (index 0) of the Nodes collection.
    LinksTreeView.Nodes(0).ToggleExpandState()

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNode ToggleExpandState Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>TreeNode ToggleExpandState Example</h3>

      <asp:TreeView id="LinksTreeView"
        Font-Names= "Arial"
        ForeColor="Blue"
        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"
            Expanded="true">

            <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> 

      <hr />

      <asp:CheckBox id="ToggleExpandStateCheckBox"
        Text="Expand Table of Contents node"
        Checked="true" 
        AutoPostBack="true"
        OnCheckedChanged="Check_Changed"
        runat="server"/>

    </form>
  </body>
</html>

.NET Framework
Available since 2.0
Return to top
Show: