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TreeNodeCollection.Count Propriété

Définition

Obtient le nombre d'éléments dans l'objet TreeNodeCollection.

public:
 property int Count { int get(); };
public int Count { get; }
member this.Count : int
Public ReadOnly Property Count As Integer

Valeur de propriété

Int32

Nombre d'éléments dans TreeNodeCollection.

Implémente

Exemples

L’exemple suivant montre comment utiliser la Count propriété pour déterminer le nombre d’éléments dans le TreeNodeCollection. Il effectue ensuite une traversée de précommande du TreeView contrôle pour afficher le texte de chaque nœud.


<%@ 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>

<%@ 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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' 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 Then

      ' Iterate through the root nodes in the Nodes property.
      Dim i As Integer

      For i = 0 To LinksTreeView.Nodes.Count - 1

        ' Display the nodes.
        DisplayChildNodeText(LinksTreeView.Nodes(i))

      Next i

    Else

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

    End If

  End Sub

  Sub DisplayChildNodeText(ByVal node As TreeNode)

    ' 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.
    Dim i As Integer

    For i = 0 To node.ChildNodes.Count - 1

      ' Recursively call the DisplayChildNodeText method to
      ' traverse the tree and display all the child nodes.
      DisplayChildNodeText(node.ChildNodes(i))

    Next i

  End Sub

</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>

Remarques

Utilisez la Count propriété pour déterminer le nombre d’éléments d’un TreeNodeCollection. Cette propriété est couramment utilisée lors de l’itération dans une collection pour déterminer la limite supérieure de la collection. La Count propriété est également couramment utilisée pour déterminer si une collection est vide.

S’applique à

Voir aussi