SelectionList.SelectedIndexChanged Event
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Occurs whenever a user changes the selection of a SelectionList object. This API is obsolete. For information about how to develop ASP.NET mobile applications, see Mobile Apps & Sites with ASP.NET.
public:
event EventHandler ^ SelectedIndexChanged;
public event EventHandler SelectedIndexChanged;
member this.SelectedIndexChanged : EventHandler
Public Custom Event SelectedIndexChanged As EventHandler
Event Type
Examples
The following code example shows how to use the SelectedIndexChanged event. It also shows how to use the Rows property on postback to expand the list.
Note
The following code sample uses the single-file code model and may not work correctly if copied directly into a code-behind file. This code sample must be copied into an empty text file that has an .aspx extension. For more information, see ASP.NET Web Forms Page Syntax Overview.
<%@ Page Language="C#"
Inherits="System.Web.UI.MobileControls.MobilePage" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>
<script runat="server">
public void Page_Load(Object sender, EventArgs e)
{
if (!IsPostBack)
{
// Create data for the list
ArrayList arr = new ArrayList();
arr.Add (new
Task ("Verify transactions", "Done"));
arr.Add (new
Task ("Check balance sheet", "Scheduled"));
arr.Add (new
Task ("Call customer", "Done"));
arr.Add (new
Task ("Issue checks", "Pending"));
arr.Add (new
Task ("Send report", "Pending"));
arr.Add (new
Task ("Attend meeting", "Scheduled"));
// Set properties for the list
SelList1.SelectType =
ListSelectType.ListBox;
SelList1.Wrapping = Wrapping.NoWrap;
SelList1.DataValueField = "Status";
SelList1.DataTextField = "TaskName";
SelList1.Rows = 3;
// Bind the list to the data
SelList1.DataSource = arr;
SelList1.DataBind ();
Label1.Text = "Select an item and click the button.";
Label2.Text = "Tasks are arranged by priority";
}
}
void ShowStatus(Object sender, EventArgs e)
{
string statusSpec = "Status: {0} is {1}";
string prioSpec = "Priority: {0}";
// Expand the list to show all items
SelList1.Rows = SelList1.Items.Count;
// Display the status
Label1.Text = String.Format(statusSpec,
SelList1.Selection.Text,
SelList1.Selection.Value);
// Display the priority
Label2.Text = String.Format(prioSpec,
(SelList1.SelectedIndex + 1));
}
// Custom class for the task data
class Task
{
private String _TaskName;
private String _Status;
public Task(String TaskName, String Status)
{
_TaskName = TaskName;
_Status = Status;
}
public String TaskName { get { return _TaskName; } }
public String Status { get { return _Status; } }
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<body>
<mobile:Form runat="server" id="Form1">
<mobile:Label runat="server" id="Label1" />
<mobile:Label runat="server" id="Label2" />
<mobile:SelectionList runat="server" id="SelList1"
OnSelectedIndexChanged="ShowStatus" />
<mobile:Command ID="Command1" runat="server"
Text="Show Status" />
</mobile:Form>
</body>
</html>
<%@ Page Language="VB"
Inherits="System.Web.UI.MobileControls.MobilePage" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>
<script runat="server">
Public Sub Page_Load(ByVal sender As Object, _
ByVal e As EventArgs)
If Not IsPostBack Then
' Create data for the list
Dim arr As New ArrayList()
arr.Add(New _
Task("Verify transactions", "Done"))
arr.Add(New _
Task("Check balance sheet", "Scheduled"))
arr.Add(New _
Task("Call customer", "Done"))
arr.Add(New _
Task("Issue checks", "Pending"))
arr.Add(New _
Task("Send report", "Pending"))
arr.Add(New _
Task("Attend meeting", "Scheduled"))
' Set properties for the list
SelList1.SelectType = _
ListSelectType.ListBox
SelList1.Wrapping = Wrapping.NoWrap
SelList1.DataValueField = "Status"
SelList1.DataTextField = "TaskName"
SelList1.Rows = 3
' Bind the list to the data
SelList1.DataSource = arr
SelList1.DataBind ()
Label1.Text = "Select an item and click the button."
Label2.Text = "Tasks are arranged by priority"
End If
End Sub
Private Sub ShowStatus(ByVal sender As Object, ByVal e As EventArgs)
Const statusSpec As String = "Status: {0} is {1}"
Const prioSpec As String = "Priority: {0}"
' Expand the list to show all items
SelList1.Rows = SelList1.Items.Count
' Display the status
Label1.Text = String.Format(statusSpec, _
SelList1.Selection.Text, _
SelList1.Selection.Value)
' Display the priority
Label2.Text = String.Format(prioSpec, _
(SelList1.SelectedIndex + 1))
End Sub
' Custom class for the task data
Class Task
Private _TaskName As String
Private _Status As String
Public Sub New(ByVal TaskName As String, _
ByVal Status As String)
_TaskName = TaskName
_Status = Status
End Sub
Public ReadOnly Property TaskName() As String
Get
Return _TaskName
End Get
End Property
Public ReadOnly Property Status() As String
Get
Return _Status
End Get
End Property
End Class
</script>
<html xmlns="http:'www.w3.org/1999/xhtml" >
<body>
<mobile:Form runat="server" id="Form1">
<mobile:Label runat="server" id="Label1" />
<mobile:Label runat="server" id="Label2" />
<mobile:SelectionList runat="server" id="SelList1"
OnSelectedIndexChanged="ShowStatus" />
<mobile:Command ID="Command1" runat="server"
Text="Show Status" />
</mobile:Form>
</body>
</html>
Remarks
Changing the selection on the client does not generate a postback event. This event is called on the server if a postback event is generated by some other control and the selection has changed.