HtmlSelect.ClearSelection Method
.NET Framework 3.0
Clears the list selection of the HtmlSelect control and sets the ListItem.Selected property of all items to false.
Namespace: System.Web.UI.HtmlControls
Assembly: System.Web (in system.web.dll)
Assembly: System.Web (in system.web.dll)
The ClearSelection method iterates through the ListItemCollection collection represented by the HtmlSelect control's Items property and sets the Selected property of each ListItem object to false.
The following code example demonstrates how to override the ClearSelection method in a custom server control so that it always clears all selected items of an HtmlSelect collection.
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL.Controls" Assembly="Samples.AspNet.JSL" %>
<%@ Page Language="VJ#" AutoEventWireup="True" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Custom HtmlSelect - ClearSelection - VJ# Example</title>
<script runat="server">
void HtmlInputButton1_ServerClick(Object sender, EventArgs e)
{
if (HtmlSelect1.get_SelectedIndex() >= 0) {
if (HtmlSelect1.get_Multiple() == true) {
Div1.set_InnerHtml("You selected:");
for (int i=0; i<=HtmlSelect1.get_Items().get_Count() - 1; i++) {
if (HtmlSelect1.get_Items().get_Item(i).
get_Selected() == true) {
Div1.set_InnerHtml(Div1.get_InnerHtml() + "<br /> " + HtmlSelect1.get_Items().get_Item(i).get_Value());
}
}
}
else {
Div1.set_InnerHtml("You selected " + HtmlSelect1.get_Value());
}
}
else {
Div1.set_InnerHtml("You did not select an item.");
}
} //HtmlInputButton1_ServerClick
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlSelect - ClearSelection - VJ# Example</h3>
<p>
<aspSample:CustomHtmlSelectClearSelection
id="HtmlSelect1" multiple
name="HtmlSelect1"
runat="server">
<option value="Option1">Option1</option>
<option value="Option2">Option2</option>
<option value="Option3">Option3</option>
<option value="Option4">Option4</option>
</aspSample:CustomHtmlSelectClearSelection>
</p>
<p>
<input
id="HtmlInputButton1"
runat="server"
type="button"
onserverclick="HtmlInputButton1_ServerClick"
value="Select"
name="HtmlInputButton1" />
</p>
<br />
<div id="Div1" runat="server"
style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
</form>
</body>
</html>
package Samples.AspNet.JSL.Controls;
public class CustomHtmlSelectClearSelection
extends System.Web.UI.HtmlControls.HtmlSelect
{
protected void ClearSelection()
{
// For each item in the Items collection,
// set the Selected property to false.
for (int i = 0; i < get_Items().get_Count(); i++) {
get_Items().get_Item(i).set_Selected(false);
}
} //ClearSelection
} //CustomHtmlSelectClearSelection
Community Additions
ADD
Show: