BaseDataList.SelectedIndexChanged Evento
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Si verifica quando in un controllo di elenco dei dati viene selezionato un elemento diverso tra gli invii al server.
public:
event EventHandler ^ SelectedIndexChanged;public event EventHandler SelectedIndexChanged;member this.SelectedIndexChanged : EventHandler Public Custom Event SelectedIndexChanged As EventHandler Tipo evento
Esempio
Nell'esempio di codice seguente viene illustrato come fornire un gestore eventi per l'evento SelectedIndexChanged in modo dichiarativo.
<%@ Page Language="C#" AutoEventWireup="True"%>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!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" >
<head runat="server">
<title>Declarative BaseDataList SelectedIndexChanged Example</title>
<script runat="server">
ICollection CreateDataSource()
{
// Create sample data for the DataGrid control.
DataTable dt = new DataTable();
DataRow dr;
// Define the columns of the table.
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
// Populate the table with sample values.
for (int i = 0; i < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * (i + 1);
dt.Rows.Add(dr);
}
// Create a DataView from the DataTable.
DataView dv = new DataView(dt);
return dv;
}
void Page_Load(Object sender, EventArgs e)
{
// Load sample data only once, when the page is first loaded.
if (!IsPostBack)
{
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
void IndexChange_Command(Object sender, EventArgs e)
{
// Display the details of the selected item.
DetailsLabel.Text =
"Item Number: " + ItemsGrid.SelectedItem.Cells[1].Text + "<br />" +
"Description: " + ItemsGrid.SelectedItem.Cells[2].Text + "<br />" +
"Price: $" + ItemsGrid.SelectedItem.Cells[3].Text + "<br />";
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>Declarative BaseDataList SelectedIndexChanged Example</h3>
Select an item:
<br /><br />
<asp:DataGrid id="ItemsGrid"
BorderColor="Black"
ShowFooter="False"
CellPadding="3"
CellSpacing="0"
HeaderStyle-BackColor="#aaaadd"
OnSelectedIndexChanged="IndexChange_Command"
runat="server">
<Columns>
<asp:ButtonColumn Text="Select"
CommandName="Select"/>
</Columns>
</asp:DataGrid>
<hr />
<table style="border-width:1; border-color:Black; margin:0">
<tr style="background-color:#aaaadd">
<td>
Details
</td>
</tr>
<tr>
<td>
<asp:Label id="DetailsLabel"
runat="server"
Text="No item selected."/>
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True"%>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!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" >
<head runat="server">
<title>Declarative BaseDataList SelectedIndexChanged Example</title>
<script runat="server">
Function CreateDataSource() As ICollection
' Create sample data for the DataGrid control.
Dim dt As DataTable = New DataTable()
Dim dr As DataRow
' Define the columns of the table.
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Integer)))
dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
' Populate the table with sample values.
Dim i As Integer
For i = 0 to 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = 1.23 * (i + 1)
dt.Rows.Add(dr)
Next i
' Create a DataView from the DataTable.
Dim dv As DataView = New DataView(dt)
Return dv
End Function
Sub Page_Load(sender As Object, e As EventArgs)
' Load sample data only once when the page is first loaded.
If Not IsPostBack Then
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub
Sub IndexChange_Command(sender As Object, e As EventArgs)
' Display the details of the selected item.
DetailsLabel.Text = _
"Item Number: " & ItemsGrid.SelectedItem.Cells(1).Text & "<br />" & _
"Description: " & ItemsGrid.SelectedItem.Cells(2).Text & "<br />" & _
"Price: $" & ItemsGrid.SelectedItem.Cells(3).Text & "<br />"
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>Declarative BaseDataList SelectedIndexChanged Example</h3>
Select an item:
<br /><br />
<asp:DataGrid id="ItemsGrid"
BorderColor="Black"
ShowFooter="False"
CellPadding="3"
CellSpacing="0"
HeaderStyle-BackColor="#aaaadd"
OnSelectedIndexChanged="IndexChange_Command"
runat="server">
<Columns>
<asp:ButtonColumn Text="Select"
CommandName="Select"/>
</Columns>
</asp:DataGrid>
<hr />
<table border="1" style="border-color:Black; margin:0">
<tr style="background-color:#aaaadd">
<td>
Details
</td>
</tr>
<tr>
<td>
<asp:Label id="DetailsLabel"
runat="server"
Text="No item selected."/>
</td>
</tr>
</table>
</form>
</body>
</html>
Nell'esempio di codice seguente viene illustrato come fornire un gestore eventi per l'evento SelectedIndexChanged a livello di codice.
<%@ Page Language="C#" AutoEventWireup="True"%>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!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" >
<head runat="server">
<title>Programmatic BaseDataList SelectedIndexChanged Example</title>
<script runat="server">
ICollection CreateDataSource()
{
// Create sample data for the DataGrid control.
DataTable dt = new DataTable();
DataRow dr;
// Define the columns of the table.
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
// Populate the table with sample values.
for (int i = 0; i < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * (i + 1);
dt.Rows.Add(dr);
}
// Create a DataView from the DataTable.
DataView dv = new DataView(dt);
return dv;
}
void IndexChange_Command(Object sender, EventArgs e)
{
// Display the details of the selected item.
DetailsLabel.Text = "Item Number: " + ItemsGrid.SelectedItem.Cells[1].Text + "<br />" +
"Description: " + ItemsGrid.SelectedItem.Cells[2].Text + "<br />" +
"Price: $" + ItemsGrid.SelectedItem.Cells[3].Text + "<br />";
}
void Page_Load(Object sender, EventArgs e)
{
// Load sample data only once, when the page is first loaded.
if (!IsPostBack)
{
// Load sample data.
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
// Register event-handling methods.
ItemsGrid.SelectedIndexChanged += new EventHandler(this.IndexChange_Command);
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>Programmatic BaseDataList SelectedIndexChanged Example</h3>
Select an item:
<br /><br />
<asp:DataGrid id="ItemsGrid"
BorderColor="Black"
ShowFooter="False"
CellPadding="3"
CellSpacing="0"
HeaderStyle-BackColor="#aaaadd"
runat="server">
<Columns>
<asp:ButtonColumn Text="Select"
CommandName="Select"/>
</Columns>
</asp:DataGrid>
<hr />
<table border="1" style="border-color:Black; margin:0">
<tr style="background-color:#aaaadd">
<td>
Details
</td>
</tr>
<tr>
<td>
<asp:Label id="DetailsLabel"
runat="server"
Text="No item selected."/>
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True"%>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!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" >
<head runat="server">
<title>Programmatic BaseDataList SelectedIndexChanged Example</title>
<script runat="server">
Function CreateDataSource() As ICollection
' Create sample data for the DataGrid control.
Dim dt As DataTable = New DataTable()
Dim dr As DataRow
' Define the columns of the table.
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Integer)))
dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
' Populate the table with sample values.
Dim i As Integer
For i = 0 to 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = 1.23 * (i + 1)
dt.Rows.Add(dr)
Next i
' Create a DataView from the DataTable.
Dim dv As DataView = New DataView(dt)
Return dv
End Function
Sub Page_Load(sender As Object, e As EventArgs)
' Load sample data only once, when the page is first loaded.
If Not IsPostBack Then
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
' Register event-handling methods.
AddHandler ItemsGrid.SelectedIndexChanged, AddressOf IndexChange_Command
End Sub
Sub IndexChange_Command(sender As Object, e As EventArgs)
' Display the details of the selected item.
DetailsLabel.Text = "Item Number: " & ItemsGrid.SelectedItem.Cells(1).Text & "<br />" & _
"Description: " & ItemsGrid.SelectedItem.Cells(2).Text & "<br />" & _
"Price: $" & ItemsGrid.SelectedItem.Cells(3).Text & "<br />"
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>Programmatic BaseDataList SelectedIndexChanged Example</h3>
Select an item:
<br /><br />
<asp:DataGrid id="ItemsGrid"
BorderColor="Black"
ShowFooter="False"
CellPadding="3"
CellSpacing="0"
HeaderStyle-BackColor="#aaaadd"
DataKeyField="IntegerValue"
OnSelectedIndexChanged="IndexChange_Command"
runat="server">
<Columns>
<asp:ButtonColumn Text="Select"
CommandName="Select"/>
</Columns>
</asp:DataGrid>
<hr />
<table border="1" style="border-color:Black; margin:0">
<tr style="background-color:#aaaadd">
<td>
Details
</td>
</tr>
<tr>
<td>
<asp:Label id="DetailsLabel"
runat="server"
Text="No item selected."/>
</td>
</tr>
</table>
</form>
</body>
</html>
Commenti
L'evento SelectedIndexChanged viene generato quando viene selezionato un elemento diverso in un controllo elenco di dati tra post al server.
Per altre informazioni su come gestire gli eventi, vedere la gestione e generazione di eventi.
Si applica a
Vedi anche
Collabora con noi su GitHub
L'origine di questo contenuto è disponibile in GitHub, in cui è anche possibile creare ed esaminare i problemi e le richieste pull. Per ulteriori informazioni, vedere la guida per i collaboratori.
Commenti e suggerimenti
Presto disponibile: Nel corso del 2024 verranno gradualmente disattivati i problemi di GitHub come meccanismo di feedback per il contenuto e ciò verrà sostituito con un nuovo sistema di feedback. Per altre informazioni, vedere https://aka.ms/ContentUserFeedback.
Invia e visualizza il feedback per