HtmlSelect.ClearSelection Méthode
Définition
Important
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Efface la sélection de liste du contrôle HtmlSelect et affecte à la propriété Selected de tous les éléments la valeur false.
protected:
virtual void ClearSelection();protected virtual void ClearSelection ();abstract member ClearSelection : unit -> unit
override this.ClearSelection : unit -> unitProtected Overridable Sub ClearSelection ()Exemples
L’exemple de code suivant montre comment remplacer la ClearSelection méthode dans un contrôle serveur personnalisé afin qu’elle efface toujours tous les éléments sélectionnés d’une HtmlSelect collection.
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" 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 - C# Example</title>
<script runat="server">
void HtmlInputButton1_ServerClick(Object sender, EventArgs e)
{
if (HtmlSelect1.SelectedIndex >= 0)
{
if (HtmlSelect1.Multiple == true)
{
Div1.InnerHtml = "You selected:";
for (int i=0; i<=HtmlSelect1.Items.Count - 1; i++)
{
if (HtmlSelect1.Items[i].Selected == true)
{
Div1.InnerHtml += "<br /> " + HtmlSelect1.Items[i].Value;
}
}
}
else
{
Div1.InnerHtml = "You selected " + HtmlSelect1.Value;
}
}
else
{
Div1.InnerHtml = "You did not select an item.";
}
}
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlSelect - ClearSelection - C# 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>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" 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 - VB.NET Example</title>
<script runat="server">
Sub HtmlInputButton1_ServerClick(sender As Object, e As EventArgs)
If HtmlSelect1.SelectedIndex >= 0 Then
If HtmlSelect1.Multiple = True Then
Div1.InnerHtml = "You selected:"
Dim i As Integer
For i = 0 To HtmlSelect1.Items.Count - 1
If HtmlSelect1.Items(i).Selected = True Then
Div1.InnerHtml += "<br /> " & HtmlSelect1.Items(i).Value
End If
Next i
Else
Div1.InnerHtml = "You selected " & HtmlSelect1.Value
End If
Else
Div1.InnerHtml = "You did not select an item."
End If
End Sub
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlSelect - ClearSelection - VB.NET 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>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomHtmlSelectClearSelection : System.Web.UI.HtmlControls.HtmlSelect
{
protected override void ClearSelection()
{
// For each item in the Items collection,
// set the Selected property to false.
for (int i=0; i < Items.Count; i++)
Items[i].Selected = false;
}
}
}
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomHtmlSelectClearSelection
Inherits System.Web.UI.HtmlControls.HtmlSelect
Protected Overrides Sub ClearSelection()
' For each item in the Items collection,
' set the Selected property to false.
Dim i As Integer
For i = 0 To Items.Count - 1
Items(i).Selected = False
Next i
End Sub
End Class
Remarques
La ClearSelection méthode itère dans la collection représentée par HtmlSelect la ListItemCollection propriété du Items contrôle et définit la Selected propriété de chaque ListItem objet falsesur .