HtmlSelect.ClearSelection Method
.NET Framework 2.0
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" %>
<HTML>
<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>
<p>
<DIV id="Div1" runat="server"
style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px"
ms_positioning="FlowLayout" />
</p>
</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
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
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