通过

TreeNodeCollection.Clear 方法

  • 参考

定义

命名空间:
System.Web.UI.WebControls
程序集:
System.Web.dll

清空 TreeNodeCollection 对象。

public:
 void Clear();
public void Clear ();
member this.Clear : unit -> unit
Public Sub Clear ()

示例

下面的示例演示如何使用 Clear 该方法以编程方式清空 a TreeNodeCollection。 请注意， Nodes 属性 ChildNodes 返回对象 TreeNodeCollection 。


<%@ 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 (!IsPostBack)
    {

      // Use the Add and Remove methods to programmatically 
      // remove the Appendix C node and replace it with a new 
      // node. 
      LinksTreeView.Nodes.Remove(LinksTreeView.Nodes[3]);
      LinksTreeView.Nodes.Add(new TreeNode("New Appendix C"));

      // Use the AddAt and RemoveAt methods to programmatically 
      // remove the Chapter One node and replace it with a new node.
      LinksTreeView.Nodes[0].ChildNodes.RemoveAt(0);
      LinksTreeView.Nodes[0].ChildNodes.AddAt(0, new TreeNode("New Chapter One"));

      // Use the Clear method to remove all the child nodes of the 
      // Chapter Two node.
      LinksTreeView.Nodes[0].ChildNodes[1].ChildNodes.Clear();

    }

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNodeCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeNodeCollection 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>

    </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 Not IsPostBack Then

      ' Use the Add and Remove methods to programmatically 
      ' remove the Appendix C node and replace it with a new 
      ' node. 
      LinksTreeView.Nodes.Remove(LinksTreeView.Nodes(3))
      LinksTreeView.Nodes.Add(New TreeNode("New Appendix C"))

      ' Use the AddAt and RemoveAt methods to programmatically 
      ' remove the Chapter One node and replace it with a new node.
      LinksTreeView.Nodes(0).ChildNodes.RemoveAt(0)
      LinksTreeView.Nodes(0).ChildNodes.AddAt(0, New TreeNode("New Chapter One"))

      ' Use the Clear method to remove all the child nodes of the 
      ' Chapter Two node.
      LinksTreeView.Nodes(0).ChildNodes(1).ChildNodes.Clear()

    End If

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNodeCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeNodeCollection 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>

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

注解

使用该方法Clear从TreeNodeCollection中删除每个TreeNode对象。

备注

若要从集合中删除单个节点，请使用 Remove 或 RemoveAt 方法。

适用于

另请参阅