DropDownList.SelectedIndex Property
Definition
Important
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Gets or sets the index of the selected item in the DropDownList control.
public:
virtual property int SelectedIndex { int get(); void set(int value); };public override int SelectedIndex { get; set; }member this.SelectedIndex : int with get, setPublic Overrides Property SelectedIndex As IntegerProperty Value
The index of the selected item in the DropDownList control. The default value is 0, which selects the first item in the list.
Examples
The following code example demonstrates how to use the SelectedIndex property to determine the selected item in the DropDownList control.
<%@ 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" >
<script runat="server" >
void Selection_Change(Object sender, EventArgs e)
{
// Set the title format based on the value selected from the
// DropDownList control. The SelectedIndex property can be used
// to determine an enumeration value. Simply cast the value to
// the appropriate enumeration type. Note that the value might
// need to be adjusted if the enumeration type is not zero-based.
Calendar1.TitleFormat = (TitleFormat)ModeList.SelectedIndex;
}
</script>
<head runat="server">
<title> DropDownList SelectedIndex Example </title>
</head>
<body>
<form id="form1" runat="server">
<h3> DropDownList SelectedIndex Example </h3>
Choose the title format.
<br /><br />
<asp:Calendar id="Calendar1"
ShowGridLines="True"
ShowTitle="True"
runat="server"/>
<br /><br />
<table cellpadding="5">
<tr>
<td>
Format:
</td>
</tr>
<tr>
<td>
<asp:DropDownList id="ModeList"
AutoPostBack="True"
OnSelectedIndexChanged="Selection_Change"
runat="server">
<asp:ListItem> Month </asp:ListItem>
<asp:ListItem Selected="True"> MonthYear </asp:ListItem>
</asp:DropDownList>
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ 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" >
<script runat="server" >
Sub Selection_Change(sender As Object, e As EventArgs)
' Set the title format based on the value selected from the
' DropDownList control. The SelectedIndex property can be used
' to determine an enumeration value. Simply cast the value to
' the appropriate enumeration type. Note that the value might
' need to be adjusted if the enumeration type is not zero-based.
Calendar1.TitleFormat = CType(ModeList.SelectedIndex, TitleFormat)
End Sub
</script>
<head runat="server">
<title> DropDownList SelectedIndex Example </title>
</head>
<body>
<form id="form1" runat="server">
<h3> DropDownList SelectedIndex Example </h3>
Choose the title format.
<br /><br />
<asp:Calendar id="Calendar1"
ShowGridLines="True"
ShowTitle="True"
runat="server"/>
<br /><br />
<table cellpadding="5">
<tr>
<td>
Format:
</td>
</tr>
<tr>
<td>
<asp:DropDownList id="ModeList"
AutoPostBack="True"
OnSelectedIndexChanged="Selection_Change"
runat="server">
<asp:ListItem> Month </asp:ListItem>
<asp:ListItem Selected="True"> MonthYear </asp:ListItem>
</asp:DropDownList>
</td>
</tr>
</table>
</form>
</body>
</html>
Remarks
Use the SelectedIndex property to programmatically specify or determine the index of the selected item from the DropDownList control. An item is always selected in the DropDownList control. You cannot clear the selection from every item in the list at the same time.
Note
The indexes for the items in the DropDownList control are zero-based.
