TreeNodeCollection.Count Eigenschap
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.
Hiermee haalt u het aantal items in het TreeNodeCollection object op.
public:
property int Count { int get(); };public int Count { get; }member this.Count : intPublic ReadOnly Property Count As IntegerWaarde van eigenschap
Het aantal items in de TreeNodeCollection.
Implementeringen
Voorbeelden
In het volgende voorbeeld ziet u hoe u de Count eigenschap gebruikt om het aantal items in de TreeNodeCollectioneigenschap te bepalen. Vervolgens wordt een doorkruising van de volgorde van het TreeView besturingselement uitgevoerd om de tekst van elk knooppunt weer te geven.
<%@ 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>
Opmerkingen
Gebruik de Count eigenschap om het aantal items in een TreeNodeCollectionte bepalen. Deze eigenschap wordt vaak gebruikt bij het doorlopen van een verzameling om de bovengrens van de verzameling te bepalen. De Count eigenschap wordt ook vaak gebruikt om te bepalen of een verzameling leeg is.
