TreeView.TreeNodeCheckChanged Kejadian
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Terjadi ketika kotak centang dalam TreeView kontrol mengubah status antara postingan ke server.
public:
event System::Web::UI::WebControls::TreeNodeEventHandler ^ TreeNodeCheckChanged;
public event System.Web.UI.WebControls.TreeNodeEventHandler TreeNodeCheckChanged;
member this.TreeNodeCheckChanged : System.Web.UI.WebControls.TreeNodeEventHandler
Public Custom Event TreeNodeCheckChanged As TreeNodeEventHandler
Jenis Acara
Contoh
Contoh kode berikut menunjukkan cara menggunakan TreeNodeCheckChanged peristiwa untuk memperbarui Label kontrol saat kotak TreeView centang status perubahan kontrol antara postingan ke server.
<%@ 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 LinksTreeView_CheckChanged(Object sender, TreeNodeEventArgs e)
{
if(LinksTreeView.CheckedNodes.Count > 0)
{
// Clear the message label.
Message.Text = "You selected: <br /><br />";
// Iterate through the CheckedNodes collection and display
// the selected nodes.
foreach (TreeNode node in LinksTreeView.CheckedNodes)
{
Message.Text += node.Text + "<br />";
}
}
else
{
Message.Text = "No items selected.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TreeView CheckChanged Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>TreeView CheckChanged Example</h3>
<!-- Set the ShowCheckBoxes property declaratively. -->
<!-- Because the ShowCheckBoxes property uses a flag -->
<!-- enumeration, you can combine multiple values by -->
<!-- using the bitwise OR operator. In declarative -->
<!-- syntax, this is done using a comma separated -->
<!-- list. -->
<asp:TreeView id="LinksTreeView"
ForeColor="Blue"
ExpandDepth="2"
ShowCheckBoxes="Parent,Leaf"
OnTreeNodeCheckChanged="LinksTreeView_CheckChanged"
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"
SelectAction="None">
<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>
<br /><br />
<asp:Button id="Submit"
Text="Select Items"
runat="server"/>
<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 LinksTreeView_CheckChanged(ByVal sender As Object, ByVal e As TreeNodeEventArgs)
If LinksTreeView.CheckedNodes.Count > 0 Then
' Clear the message label.
Message.Text = "You selected: <br /><br />"
' Iterate through the CheckedNodes collection and display
' the selected nodes.
Dim node As TreeNode
For Each node In LinksTreeView.CheckedNodes
Message.Text &= node.Text & "<br />"
Next
Else
Message.Text = "No items selected."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TreeView CheckChanged Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>TreeView CheckChanged Example</h3>
<!-- Set the ShowCheckBoxes property declaratively. -->
<!-- Because the ShowCheckBoxes property uses a flag -->
<!-- enumeration, you can combine multiple values by -->
<!-- using the bitwise OR operator. In declarative -->
<!-- syntax, this is done using a comma separated -->
<!-- list. -->
<asp:TreeView id="LinksTreeView"
ForeColor="Blue"
ExpandDepth="2"
ShowCheckBoxes="Parent,Leaf"
OnTreeNodeCheckChanged="LinksTreeView_CheckChanged"
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"
SelectAction="None">
<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>
<br /><br />
<asp:Button id="Submit"
Text="Select Items"
runat="server"/>
<br /><br />
<asp:Label id="Message"
runat="server"/>
</form>
</body>
</html>
Keterangan
Peristiwa TreeNodeCheckChanged dimunculkan ketika kotak centang dalam TreeView kontrol mengubah status antara postingan ke server. Ini memungkinkan Anda untuk menyediakan metode penanganan peristiwa yang melakukan rutinitas kustom, seperti memperbarui database atau konten yang ditampilkan, setiap kali peristiwa ini terjadi.
Meskipun TreeNodeCheckChanged peristiwa diaktifkan saat diposting kembali, mengubah kotak centang tidak menyebabkan posting kembali.
Untuk informasi selengkapnya tentang cara menangani peristiwa, lihat Menangani dan Menaikkan Peristiwa.