TreeNodeCollection.Clear Methode
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Het object leegt TreeNodeCollection .
public:
void Clear();public void Clear();member this.Clear : unit -> unitPublic Sub Clear ()Voorbeelden
In het volgende voorbeeld ziet u hoe u de Clear methode gebruikt om programmatisch een leeg te TreeNodeCollectionmaken. U ziet dat de Nodes en ChildNodes eigenschappen een TreeNodeCollection object retourneren.
<%@ 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>
Opmerkingen
Gebruik de Clear methode om elk TreeNode object uit het TreeNodeCollectionobject te verwijderen.
Note
Als u een afzonderlijk knooppunt uit de verzameling wilt verwijderen, gebruikt u de Remove of RemoveAt methode.
