ListBox.SelectionMode Property
Gets or sets the selection mode of the ListBox control.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in System.Web.dll)
<asp:ListBox SelectionMode="ListSelectionMode" />
Property Value
Type: System.Web.UI.WebControls.ListSelectionModeOne of the ListSelectionMode values. The default value is Single.
| Exception | Condition |
|---|---|
| ArgumentOutOfRangeException | The specified selection mode is not one of the ListSelectionMode values. |
Use the SelectionMode property to specify the mode behavior of the ListBox control. Setting this property to ListSelectionMode.Single indicates only a single item can be selected from the ListBox control, while ListSelectionMode.Multiple specifies multiple items can be selected.
The value of the SelectionMode property is stored in view state.
| Topic | Location |
|---|---|
| How to: Add ListBox Web Server Controls to a Web Forms Page | Building ASP .NET Web Applications |
| How to: Add ListBox Web Server Controls to a Web Forms Page | Building ASP .NET Web Applications |
| How to: Set the Selection in List Web Server Controls (Visual Studio) | Building ASP .NET Web Applications in Visual Studio |
The following example illustrates how to use the SelectionMode property to allow the user to select multiple selections from the ListBox 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" > <head runat="server"> <title>ListBox Example</title> <script runat="server"> void SubmitBtn_Click(Object sender, EventArgs e) { Message.Text = "You chose: <br />"; // Iterate through the Items collection of the ListBox and // display the selected items. foreach (ListItem item in ListBox1.Items) { if(item.Selected) { Message.Text += item.Text + "<br />"; } } } </script> </head> <body> <h3>ListBox Example</h3> <form id="form1" runat="server"> Select items from the list and click Submit. <br /> <asp:ListBox id="ListBox1" Rows="6" Width="100px" SelectionMode="Multiple" runat="server"> <asp:ListItem Selected="True">Item 1</asp:ListItem> <asp:ListItem>Item 2</asp:ListItem> <asp:ListItem>Item 3</asp:ListItem> <asp:ListItem>Item 4</asp:ListItem> <asp:ListItem>Item 5</asp:ListItem> <asp:ListItem>Item 6</asp:ListItem> </asp:ListBox> <br /><br /> <asp:button id="Button1" Text="Submit" OnClick="SubmitBtn_Click" runat="server" /> <br /><br /> <asp:Label id="Message" runat="server"/> </form> </body> </html>
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
