ListControl.SelectedItem Propriedade
Definição
Importante
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Obtém o item selecionado com o índice mais baixo no controle de lista.
public:
virtual property System::Web::UI::WebControls::ListItem ^ SelectedItem { System::Web::UI::WebControls::ListItem ^ get(); };
[System.ComponentModel.Browsable(false)]
public virtual System.Web.UI.WebControls.ListItem SelectedItem { get; }
[<System.ComponentModel.Browsable(false)>]
member this.SelectedItem : System.Web.UI.WebControls.ListItem
Public Overridable ReadOnly Property SelectedItem As ListItem
Valor da propriedade
O menor item indexado selecionado do controle de lista. O padrão é null
.
- Atributos
Exemplos
O exemplo a RadioButtonList seguir demonstra como usar SelectedItem para obter as propriedades individuais do item selecionado no momento e exibir esse item e seu valor.
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<!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" >
<script language="c#" runat="server">
ICollection CreateDataSource() {
DataTable dt = new DataTable();
DataRow dr;
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("DateTimeValue", typeof(DateTime)));
dt.Columns.Add(new DataColumn("BoolValue", typeof(bool)));
dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
for (int i = 0; i < 9; i++) {
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = DateTime.Now;
dr[3] = (i % 2 != 0) ? true : false;
dr[4] = 1.23 * (i+1);
dt.Rows.Add(dr);
}
DataView dv = new DataView(dt);
return dv;
}
void Page_Load(Object sender, EventArgs e) {
if (!IsPostBack) {
RadioButtonList1.DataSource = CreateDataSource();
RadioButtonList1.DataTextField="StringValue";
RadioButtonList1.DataValueField="CurrencyValue";
RadioButtonList1.DataBind();
}
}
void Index_Changed(Object sender, EventArgs e) {
Label1.Text = "You selected " + RadioButtonList1.SelectedItem.Text +
" with a value of $" + RadioButtonList1.SelectedItem.Value +
".";
}
</script>
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:RadioButtonList id="RadioButtonList1"
OnSelectedIndexChanged="Index_Changed"
AutoPostBack="true"
runat="server"/>
<br />
<asp:Label id="Label1" runat="server"/>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<!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" >
<script language="vb" runat="server">
Function CreateDataSource() As ICollection
Dim dt As New DataTable()
Dim dr As DataRow
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
dt.Columns.Add(New DataColumn("DateTimeValue", GetType(DateTime)))
dt.Columns.Add(New DataColumn("BoolValue", GetType(Boolean)))
dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
Dim i As Integer
For i = 0 To 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " + i.ToString()
dr(2) = DateTime.Now
If (i Mod 2) <> 0 Then
dr(3) = True
Else
dr(3) = False
End If
dr(4) = 1.23 *(i + 1)
dt.Rows.Add(dr)
Next i
Dim dv As New DataView(dt)
Return dv
End Function
Sub Page_Load(sender As Object, e As EventArgs)
If Not IsPostBack Then
RadioButtonList1.DataSource = CreateDataSource()
RadioButtonList1.DataTextField = "StringValue"
RadioButtonList1.DataValueField = "CurrencyValue"
RadioButtonList1.DataBind()
End If
End Sub
Sub Index_Changed(sender As Object, e As EventArgs)
Label1.Text = "You selected " & RadioButtonList1.SelectedItem.Text & _
" with a value of : " & RadioButtonList1.SelectedItem.Value & "."
End Sub
</script>
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:RadioButtonList id="RadioButtonList1"
OnSelectedIndexChanged="Index_Changed"
AutoPostBack="true"
runat="server"/>
<br />
<asp:Label id="Label1" runat="server"/>
</form>
</body>
</html>
Comentários
Se o controle de lista permitir apenas uma única seleção, use essa propriedade para obter as propriedades individuais do item selecionado. Se o controle de lista permitir várias seleções, use essa propriedade para obter as propriedades do item indexado mais baixo selecionado no controle de lista.