Export (0) Print
Expand All

TreeNodeCollection.Contains Method

Note: This method is new in the .NET Framework version 2.0.

Determines whether the specified TreeNode object is in the collection.

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

public bool Contains (
	TreeNode c
)
public boolean Contains (
	TreeNode c
)
public function Contains (
	c : TreeNode
) : boolean

Parameters

c

The TreeNode object to find.

Return Value

true if the specified TreeNode object is contained in the collection; otherwise, false.

Use the Contains method to determine whether a TreeNode object is contained in the TreeNodeCollection. This method is commonly used to test for the existence of a TreeNode object before performing a task, such as adding or removing the node from the collection.

The following example demonstrates how to use the Contains method to determine whether the selected node is in the Nodes collection. Notice that the Nodes property returns a TreeNodeCollection object.


<%@ Page Language="C#" %>

<script runat="server">

  void Node_Changed(Object sender, EventArgs e)
  {

    // Determine whether the Nodes collection contains the selected node
    // and display the appropriate message.
    if(LinksTreeView.Nodes.Contains(LinksTreeView.SelectedNode))
    {

      Message.Text = "The index of " + LinksTreeView.SelectedNode.Text + 
        " is " +  LinksTreeView.Nodes.IndexOf(LinksTreeView.SelectedNode).ToString();

    }
    else
    {

      Message.Text = "The selected node is not a root node.";

    }

  }

</script>

<html>
  <body>
    <form runat="server">
    
      <h3>TreeNodeCollection Contains Example</h3>
      
      <h5>Click a root node.</h5>
    
      <asp:TreeView id="LinksTreeView"
        Font-Name= "Arial"
        ForeColor="Blue"
        OnSelectedNodeChanged="Node_Changed"  
        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="Subtopic 1"/>
                  <asp:TreeNode Text="Subtopic 2"/>
                
                </asp:TreeNode>
                <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:Label id="Message"
        runat="server"/>

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


Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

Community Additions

ADD
Show:
© 2015 Microsoft