DetailsViewCommandEventHandler Delegato
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.
Rappresenta il metodo che gestisce l'evento ItemCommand di un controllo DetailsView.
public delegate void DetailsViewCommandEventHandler(System::Object ^ sender, DetailsViewCommandEventArgs ^ e);public delegate void DetailsViewCommandEventHandler(object sender, DetailsViewCommandEventArgs e);type DetailsViewCommandEventHandler = delegate of obj * DetailsViewCommandEventArgs -> unitPublic Delegate Sub DetailsViewCommandEventHandler(sender As Object, e As DetailsViewCommandEventArgs)Parametri
- sender
- Object
Origine dell'evento.
Oggetto DetailsViewCommandEventArgs che contiene i dati dell'evento.
Esempio
Nell'esempio di codice seguente viene illustrato come aggiungere un DetailsViewCommandEventHandler delegato a livello di codice all'evento ItemCommand di un DetailsView controllo . In questo esempio viene usato il modello di codifica a file singolo.
<%@ page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load(Object sender, EventArgs e)
{
// Create a new DetailsView object.
DetailsView customerDetailsView = new DetailsView();
// Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView";
customerDetailsView.DataSourceID = "DetailsViewSource";
customerDetailsView.AutoGenerateRows = true;
customerDetailsView.AllowPaging = true;
customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };
// Add a button field to the DetailsView control.
ButtonField field = new ButtonField();
field.ButtonType = ButtonType.Link;
field.CausesValidation = false;
field.Text = "Add to List";
field.CommandName="Add";
customerDetailsView.Fields.Add(field);
// Programmatically register the event-handling method
// for the ItemDeleting event of a DetailsView control.
customerDetailsView.ItemCommand
+= new DetailsViewCommandEventHandler(
this.CustomerDetailsView_ItemCommand);
// Add the DetailsView object to the Controls collection
// of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView);
}
void CustomerDetailsView_ItemCommand(Object sender,
DetailsViewCommandEventArgs e)
{
// Use the CommandName property to determine which button
// was clicked.
if (e.CommandName == "Add")
{
// Get the DetailsView control that raised the event.
DetailsView customerDetailsView = (DetailsView)e.CommandSource;
// Add the current customer to the customer list.
// Get the row that contains the company name. In this
// example, the company name is in the second row (index 1)
// of the DetailsView control.
DetailsViewRow row = customerDetailsView.Rows[1];
// Get the company's name from the appropriate cell.
// In this example, the company name is in the second cell
// (index 1) of the row.
String name = row.Cells[1].Text;
// Create a ListItem object with the company name.
ListItem item = new ListItem(name);
// Add the ListItem object to the ListBox, if the
// item doesn't already exist.
if (!CustomerListBox.Items.Contains(item))
{
CustomerListBox.Items.Add(item);
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewCommandEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewCommandEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:placeholder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
Selected Customers:<br/>
<asp:listbox id="CustomerListBox"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
<%@ page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Create a new DetailsView object.
Dim customerDetailsView As New DetailsView()
' Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView"
customerDetailsView.DataSourceID = "DetailsViewSource"
customerDetailsView.AutoGenerateRows = True
customerDetailsView.AllowPaging = True
Dim keyArray() As String = {"CustomerID"}
customerDetailsView.DataKeyNames = keyArray
' Add a button field to the DetailsView control.
Dim field As New ButtonField()
field.ButtonType = ButtonType.Link
field.CausesValidation = False
field.Text = "Add to List"
field.CommandName = "Add"
customerDetailsView.Fields.Add(field)
' Programmatically register the event-handling method
' for the ItemDeleting event of a DetailsView control.
AddHandler customerDetailsView.ItemCommand, _
AddressOf CustomerDetailsView_ItemCommand
' Add the DetailsView object to the Controls collection
' of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView)
End Sub
Sub CustomerDetailsView_ItemCommand(ByVal sender As Object, _
ByVal e As DetailsViewCommandEventArgs)
' Use the CommandName property to determine which button
' was clicked.
If e.CommandName = "Add" Then
' Get the DetailsView control that raised the event.
Dim customerDetailsView As DetailsView = _
CType(e.CommandSource, DetailsView)
' Add the current customer to the customer list.
' Get the row that contains the company name. In this
' example, the company name is in the second row (index 1)
' of the DetailsView control.
Dim row As DetailsViewRow = customerDetailsView.Rows(1)
' Get the company's name from the appropriate cell.
' In this example, the company name is in the second cell
' (index 1) of the row.
Dim name As String = row.Cells(1).Text
' Create a ListItem object with the company name.
Dim item As New ListItem(name)
' Add the ListItem object to the ListBox, if the
' item doesn't already exist.
If Not CustomerListBox.Items.Contains(item) Then
CustomerListBox.Items.Add(item)
End If
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewCommandEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewCommandEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:placeholder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
Selected Customers:<br/>
<asp:listbox id="CustomerListBox"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Nell'esempio di codice seguente viene illustrata una versione del modello di codifica code-behind dell'esempio precedente. Per il funzionamento di questo esempio, è necessario copiare il codice seguente nel file code-behind associato.
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!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>DetailsViewCommandEventHandler Example</title>
</head>
<body>
<form id="Form1" runat="server">
<h3>DetailsViewCommandEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:placeholder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
Selected Customers:<br/>
<asp:listbox id="CustomerListBox"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
connectionstring="
<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="DefaultVB.aspx.vb" Inherits="DefaultVB" %>
<!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>DetailsViewCommandEventHandler Example</title>
</head>
<body>
<form id="Form1" runat="server">
<h3>DetailsViewCommandEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:placeholder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
Selected Customers:<br/>
<asp:listbox id="CustomerListBox"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Nell'esempio di codice seguente viene illustrato il file code-behind per l'esempio precedente.
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
// Create a new DetailsView object.
DetailsView customerDetailsView = new DetailsView();
// Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView";
customerDetailsView.DataSourceID = "DetailsViewSource";
customerDetailsView.AutoGenerateRows = true;
customerDetailsView.AllowPaging = true;
customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };
// Add a button field to the DetailsView control.
ButtonField field = new ButtonField();
field.ButtonType = ButtonType.Link;
field.CausesValidation = false;
field.Text = "Add to List";
field.CommandName = "Add";
customerDetailsView.Fields.Add(field);
// Programmatically register the event-handling method
// for the ItemDeleting event of a DetailsView control.
customerDetailsView.ItemCommand += new DetailsViewCommandEventHandler(this.CustomerDetailsView_ItemCommand);
// Add the DetailsView object to the Controls collection
// of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView);
}
void CustomerDetailsView_ItemCommand(Object sender, DetailsViewCommandEventArgs e)
{
// Use the CommandName property to determine which button
// was clicked.
if (e.CommandName == "Add")
{
// Get the DetailsView control that raised the event.
DetailsView customerDetailsView = (DetailsView)sender;
// Add the current customer to the customer list.
// Get the row that contains the company name. In this
// example, the company name is in the second row (index 1)
// of the DetailsView control.
DetailsViewRow row = customerDetailsView.Rows[1];
// Get the company's name from the appropriate cell.
// In this example, the company name is in the second cell
// (index 1) of the row.
String name = row.Cells[1].Text;
// Create a ListItem object with the company name.
ListItem item = new ListItem(name);
// Add the ListItem object to the ListBox, if the
// item doesn't already exist.
if (!CustomerListBox.Items.Contains(item))
{
CustomerListBox.Items.Add(item);
}
}
}
}
Partial Class DefaultVB
Inherits System.Web.UI.Page
Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
' Create a new DetailsView object.
Dim customerDetailsView As New DetailsView()
' Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView"
customerDetailsView.DataSourceID = "DetailsViewSource"
customerDetailsView.AutoGenerateRows = True
customerDetailsView.AllowPaging = True
Dim keyArray() As String = {"CustomerID"}
customerDetailsView.DataKeyNames = keyArray
' Add a button field to the DetailsView control.
Dim field As New ButtonField()
field.ButtonType = ButtonType.Link
field.CausesValidation = False
field.Text = "Add to List"
field.CommandName = "Add"
customerDetailsView.Fields.Add(field)
' Programmatically register the event-handling method
' for the ItemDeleting event of a DetailsView control.
AddHandler customerDetailsView.ItemCommand, AddressOf CustomerDetailsView_ItemCommand
' Add the DetailsView object to the Controls collection
' of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView)
End Sub
Sub CustomerDetailsView_ItemCommand(ByVal sender As Object, ByVal e As DetailsViewCommandEventArgs)
' Use the CommandName property to determine which button
' was clicked.
If e.CommandName = "Add" Then
' Get the DetailsView control that raised the event.
Dim customerDetailsView As DetailsView = CType(sender, DetailsView)
' Add the current customer to the customer list.
' Get the row that contains the company name. In this
' example, the company name is in the second row (index 1)
' of the DetailsView control.
Dim row As DetailsViewRow = customerDetailsView.Rows(1)
' Get the company's name from the appropriate cell.
' In this example, the company name is in the second cell
' (index 1) of the row.
Dim name As String = row.Cells(1).Text
' Create a ListItem object with the company name.
Dim item As New ListItem(name)
' Add the ListItem object to the ListBox, if the
' item doesn't already exist.
If Not CustomerListBox.Items.Contains(item) Then
CustomerListBox.Items.Add(item)
End If
End If
End Sub
End Class
Nell'esempio di codice seguente viene illustrato come aggiungere in modo dichiarativo un DetailsViewCommandEventHandler delegato all'evento ItemCommand di un DetailsView controllo .
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void CustomerDetailView_ItemCommand(Object sender, DetailsViewCommandEventArgs e)
{
// Use the CommandName property to determine which button
// was clicked.
if (e.CommandName == "Add")
{
// Add the current store to the contact list.
// Get the row that contains the store name. In this
// example, the store name is in the second row (index 1)
// of the DetailsView control.
DetailsViewRow row = CustomerDetailView.Rows[1];
// Get the store's name from the appropriate cell.
// In this example, the store name is in the second cell
// (index 1) of the row.
String name = row.Cells[1].Text;
// Create a ListItem object with the store's name.
ListItem item = new ListItem(name);
// Add the ListItem object to the ListBox, if the
// item doesn't already exist.
if (!ContactListBox.Items.Contains(item))
{
ContactListBox.Items.Add(item);
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>
DetailsView ItemCommand Example</title>
</head>
<body>
<form id="Form1" runat="server">
<h3>
DetailsView ItemCommand Example</h3>
<asp:DetailsView ID="CustomerDetailView"
DataSourceID="DetailsViewSource"
AutoGenerateRows="false"
DataKeyNames="CustomerID"
AllowPaging="true"
OnItemCommand="CustomerDetailView_ItemCommand"
runat="server">
<FieldHeaderStyle BackColor="Navy" ForeColor="White" />
<Fields>
<asp:BoundField DataField="CustomerID" HeaderText="Store ID" />
<asp:BoundField DataField="CompanyName" HeaderText="Store Name" />
<asp:BoundField DataField="City" HeaderText="City" />
<asp:ButtonField CommandName="Add" Text="Add Contact" />
</Fields>
</asp:DetailsView>
<hr />
Contacts:<br />
<asp:ListBox ID="ContactListBox" runat="server" />
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:SqlDataSource ID="DetailsViewSource" runat="server"
ConnectionString=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
InsertCommand="INSERT INTO [Customers]([CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country]) VALUES (@CustomerID, @CompanyName, @Address, @City, @PostalCode, @Country)"
SelectCommand="Select [CustomerID], [CompanyName],
[Address], [City], [PostalCode], [Country] From
[Customers]">
</asp:SqlDataSource>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub CustomerDetailView_ItemCommand(ByVal sender As Object, ByVal e As DetailsViewCommandEventArgs)
' Use the CommandName property to determine which button
' was clicked.
If e.CommandName = "Add" Then
' Add the current store to the contact list.
' Get the row that contains the store name. In this
' example, the store name is in the second row (index 1)
' of the DetailsView control.
Dim row As DetailsViewRow = CustomerDetailView.Rows(1)
' Get the store's name from the appropriate cell.
' In this example, the store name is in the second cell
' (index 1) of the row.
Dim name As String = row.Cells(1).Text
' Create a ListItem object with the store's name.
Dim item As New ListItem(name)
' Add the ListItem object to the ListBox, if the
' item doesn't already exist.
If Not ContactListBox.Items.Contains(item) Then
ContactListBox.Items.Add(item)
End If
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>
DetailsView ItemCommand Example</title>
</head>
<body>
<form id="Form1" runat="server">
<h3>
DetailsView ItemCommand Example</h3>
<asp:DetailsView ID="CustomerDetailView"
DataSourceID="DetailsViewSource"
AutoGenerateRows="false"
DataKeyNames="CustomerID"
AllowPaging="true"
OnItemCommand="CustomerDetailView_ItemCommand"
runat="server">
<FieldHeaderStyle BackColor="Navy" ForeColor="White" />
<Fields>
<asp:BoundField DataField="CustomerID" HeaderText="Store ID" />
<asp:BoundField DataField="CompanyName" HeaderText="Store Name" />
<asp:BoundField DataField="City" HeaderText="City" />
<asp:ButtonField CommandName="Add" Text="Add Contact" />
</Fields>
</asp:DetailsView>
<hr />
Contacts:<br />
<asp:ListBox ID="ContactListBox" runat="server" />
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:SqlDataSource ID="DetailsViewSource" runat="server"
ConnectionString=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
InsertCommand="INSERT INTO [Customers]([CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country]) VALUES (@CustomerID, @CompanyName, @Address, @City, @PostalCode, @Country)"
SelectCommand="Select [CustomerID], [CompanyName],
[Address], [City], [PostalCode], [Country] From
[Customers]">
</asp:SqlDataSource>
</form>
</body>
</html>
Commenti
Il DetailsView controllo genera l'evento ItemCommand quando si fa clic su un pulsante all'interno di un ButtonFieldcampo di riga , CommandFieldo TemplateField . In questo modo è possibile fornire un gestore eventi che esegue una routine personalizzata ogni volta che si verifica questo evento.
Nota
Il DetailsView controllo genera anche altri eventi specializzati quando si fa clic su determinati pulsanti (pulsanti con la CommandName proprietà impostata su "Elimina", "Inserisci", "Pagina" o "Aggiorna"). Quando si usa uno di questi pulsanti, è consigliabile usare uno degli eventi specializzati forniti dal controllo ( ad esempio ItemDeleted o ItemDeleting).
Quando si crea un delegato DetailsViewCommandEventHandler, si identifica il metodo che gestirà l'evento. Per associare l'evento al gestore eventi in uso, aggiungere all'evento un'istanza del delegato. Il gestore eventi viene chiamato ogni volta che si verifica l'evento, a meno che non venga rimosso il delegato. Per altre informazioni sui delegati del gestore eventi, vedere Gestione e generazione di eventi.
Metodi di estensione
| GetMethodInfo(Delegate) |
Ottiene un oggetto che rappresenta il metodo rappresentato dal delegato specificato. |
Si applica a
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