SelectionList.SelectedIndexChanged Event

Reference

Definition

Namespace:: System.Web.UI.MobileControls

Assembly:: System.Web.Mobile.dll

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 This API is obsolete.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

EventHandler

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.

ASP.NET (C#)

<%@ 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.

Applies to

Product	Versions
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

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