ListBox.SelectionMode Property
Gets or sets the selection mode of the ListBox control.
[Visual Basic] Public Overridable Property SelectionMode As ListSelectionMode [C#] public virtual ListSelectionMode SelectionMode {get; set;} [C++] public: __property virtual ListSelectionMode get_SelectionMode(); public: __property virtual void set_SelectionMode(ListSelectionMode); [JScript] public function get SelectionMode() : ListSelectionMode; public function set SelectionMode(ListSelectionMode);
Property Value
One of the ListSelectionMode values. The default value is Single.
Exceptions
| Exception Type | Condition |
|---|---|
| ArgumentException | The specified selection mode is not one of the ListSelectionMode values. |
Remarks
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.
Example
[Visual Basic, C#] The following example illustrates how to use the SelectionMode property to allow the user to select multiple selections from the ListBox control.
[Visual Basic] <%@ Page Language="VB" AutoEventWireup="True" %> <html> <head> <script runat="server"> Sub SubmitBtn_Click(sender As Object, e As EventArgs) Message.Text = "You chose: <br>" ' Iterate through the Items collection of the ListBox and ' display the selected items. Dim item As ListItem For Each item in ListBox1.Items If item.Selected Then Message.Text &= item.Text & "<br>" End If Next End Sub Sub Selection_Change(sender As Object, e As EventArgs) ' A single-selection ListBox cannot have multiple items selected. ' Make sure only one item is selected before changing selection modes. ListBox1.SelectedIndex = 0 ' Set the selection mode. ListBox1.SelectionMode = CType(SelectionModeList.SelectedIndex, ListSelectionMode) End Sub </script> </head> <body> <h3>ListBox Example</h3> <form runat=server> Select items from the list and click Submit. <br> Choose the selection mode from the drop-down list. <br> <asp:ListBox id="ListBox1" Rows="6" Width="100px" SelectionMode="Single" 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> Selection mode: <br> <asp:DropDownList id="SelectionModeList" AutoPostBack="True" OnSelectedIndexChanged="Selection_Change" runat="server"> <asp:ListItem Selected="True">Single</asp:ListItem> <asp:ListItem>Multiple</asp:ListItem> </asp:DropDownList> <br><br> <asp:button id="Button1" Text="Submit" OnClick="SubmitBtn_Click" runat="server" /> <br><br> <asp:Label id="Message" runat="server"/> </form> </body> </html> [C#] <%@ Page Language="C#" AutoEventWireup="True" %> <html> <head> <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>"; } } } void Selection_Change(Object sender, EventArgs e) { // A single-selection ListBox cannot have multiple items selected. // Make sure only one item is selected before changing selection modes. ListBox1.SelectedIndex = 0; // Set the selection mode. ListBox1.SelectionMode = (ListSelectionMode)SelectionModeList.SelectedIndex; } </script> </head> <body> <h3>ListBox Example</h3> <form runat=server> Select items from the list and click Submit. <br> Choose the selection mode from the drop-down list. <br> <asp:ListBox id="ListBox1" Rows="6" Width="100px" SelectionMode="Single" 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> Selection mode: <br> <asp:DropDownList id="SelectionModeList" AutoPostBack="True" OnSelectedIndexChanged="Selection_Change" runat="server"> <asp:ListItem Selected="True">Single</asp:ListItem> <asp:ListItem>Multiple</asp:ListItem> </asp:DropDownList> <br><br> <asp:button id="Button1" Text="Submit" OnClick="SubmitBtn_Click" runat="server" /> <br><br> <asp:Label id="Message" runat="server"/> </form> </body> </html>
[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
See Also
ListBox Class | ListBox Members | System.Web.UI.WebControls Namespace | ListSelectionMode