SelectionList.SelectedIndexChanged Evento

  • Referência

Definição

Namespace:
System.Web.UI.MobileControls
Assembly:
System.Web.Mobile.dll

Ocorre sempre que um usuário altera a seção de um objeto SelectionList. Esta API está obsoleta. Para obter informações sobre como desenvolver aplicativos móveis ASP.NET, consulte Aplicativos Móveis & Sites com ASP.NET.

public:
 event EventHandler ^ SelectedIndexChanged;
public event EventHandler SelectedIndexChanged;
member this.SelectedIndexChanged : EventHandler 
Public Custom Event SelectedIndexChanged As EventHandler

Tipo de evento

EventHandler

Exemplos

O exemplo de código a seguir mostra como usar o SelectedIndexChanged evento . Ele também mostra como usar a Rows propriedade no postback para expandir a lista.

Observação

O exemplo de código a seguir usa o modelo de código de arquivo único e pode não funcionar corretamente se copiado diretamente em um arquivo code-behind. Este exemplo de código deve ser copiado para um arquivo de texto vazio que tenha uma extensão de .aspx. Para obter mais informações, consulte ASP.NET Visão geral da sintaxe de página dos Web Forms.

<%@ 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>

Comentários

Alterar a seleção no cliente não gera um evento de postback. Esse evento será chamado no servidor se um evento de postback for gerado por algum outro controle e a seleção tiver sido alterada.

Aplica-se a

Confira também