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TreeNodeCollection.Count Property

Gets the number of items in the TreeNodeCollection object.

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

public int Count { get; }

Property Value

Type: System.Int32
The number of items in the TreeNodeCollection.

Implements

ICollection.Count

Use the Count property to determine the number of items in a TreeNodeCollection. This property is commonly used when iterating through a collection to determine the upper bound of the collection. The Count property is also commonly used to determine whether a collection is empty.

The following example demonstrates how to use the Count property to determine the number of items in the TreeNodeCollection. It then performs a preorder traversal of the TreeView control to display the text of each node.

<%@ 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 Page_Load(Object sender, EventArgs e)
  {

    // If the TreeView control contains any root nodes, perform a 
    // preorder traversal of the tree and display the text of each node. 
    if(LinksTreeView.Nodes.Count > 0)
    {

      // Iterate through the root nodes in the Nodes property. 
      for(int i=0; i<LinksTreeView.Nodes.Count; i++)
      {

        // Display the nodes.
        DisplayChildNodeText(LinksTreeView.Nodes[i]);

      }

    }
    else
    {

      Message.Text = "The TreeView control does not have any nodes.";

    }

  }

  void DisplayChildNodeText(TreeNode node)
  {

    // Display the node's text value.
    Message.Text += node.Text + "<br />";

    // Iterate through the child nodes of the parent node passed into 
    // this method and display their values. 
    for(int i=0; i<node.ChildNodes.Count; i++)
    {

      // Recursively call the DisplayChildNodeText method to 
      // traverse the tree and display all the child nodes.
      DisplayChildNodeText(node.ChildNodes[i]);

    }

  }

</script>

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

      <h3>TreeNodeCollection Count 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="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>

      <br /><br />

      <asp:Label id="Message"
        runat="server"/>

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

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0
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