TreeNodeCollection.Contains(TreeNode) TreeNodeCollection.Contains(TreeNode) TreeNodeCollection.Contains(TreeNode) TreeNodeCollection.Contains(TreeNode) Method

Определение

Определяет, присутствует ли в коллекции указанный объект TreeNode.Determines whether the specified TreeNode object is in the collection.

public:
 bool Contains(System::Web::UI::WebControls::TreeNode ^ c);
public bool Contains (System.Web.UI.WebControls.TreeNode c);
member this.Contains : System.Web.UI.WebControls.TreeNode -> bool
Public Function Contains (c As TreeNode) As Boolean

Параметры

c
TreeNode TreeNode TreeNode TreeNode

Искомый объект TreeNode.The TreeNode object to find.

Возвраты

true, если указанный объект TreeNode содержится в коллекции; в противном случае — false.true if the specified TreeNode object is contained in the collection; otherwise, false.

Примеры

В следующем примере демонстрируется использование Contains метода для определения того, входит ли выбранный узел Nodes в коллекцию.The following example demonstrates how to use the Contains method to determine whether the selected node is in the Nodes collection. Обратите внимание Nodes , что свойство TreeNodeCollection возвращает объект.Notice that the Nodes property returns a TreeNodeCollection object.


<%@ 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 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 xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNodeCollection Contains Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeNodeCollection Contains Example</h3>
      
      <h5>Click a root node.</h5>
    
      <asp:TreeView id="LinksTreeView"
        Font-Names= "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>


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

    ' Determine whether the Nodes collection contains the selected node
    ' and display the appropriate message.
    If LinksTreeView.Nodes.Contains(LinksTreeView.SelectedNode) Then

      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."

    End If

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNodeCollection Contains Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeNodeCollection Contains Example</h3>
      
      <h5>Click a root node.</h5>
    
      <asp:TreeView id="LinksTreeView"
        Font-Names= "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>

Комментарии

Используйте метод, чтобы определить, содержится TreeNode ли TreeNodeCollectionобъект в. ContainsUse the Contains method to determine whether a TreeNode object is contained in the TreeNodeCollection. Этот метод обычно используется для проверки существования TreeNode объекта перед выполнением задачи, например добавления или удаления узла из коллекции.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.

Применяется к

Дополнительно