DetailsViewPageEventHandler Delegato
Definizione
Importante
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Rappresenta il metodo che gestisce l'evento PageIndexChanging di un controllo DetailsView.
public delegate void DetailsViewPageEventHandler(System::Object ^ sender, DetailsViewPageEventArgs ^ e);public delegate void DetailsViewPageEventHandler(object sender, DetailsViewPageEventArgs e);type DetailsViewPageEventHandler = delegate of obj * DetailsViewPageEventArgs -> unitPublic Delegate Sub DetailsViewPageEventHandler(sender As Object, e As DetailsViewPageEventArgs)Parametri
- sender
- Object
Origine dell'evento.
Oggetto DetailsViewPageEventArgs che contiene i dati dell'evento.
Esempio
Nell'esempio di codice seguente viene illustrato come aggiungere un DetailsViewPageEventHandler delegato a livello di codice all'evento PageIndexChanging 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 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.AutoGenerateEditButton = true;
customerDetailsView.AllowPaging = true;
customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };
customerDetailsView.PagerSettings.Position = PagerPosition.Bottom;
// Programmatically register the event-handling methods
// for the DetailsView control.
customerDetailsView.PageIndexChanging += new DetailsViewPageEventHandler(this.CustomerDetailsView_PageIndexChanging);
customerDetailsView.ModeChanging += new DetailsViewModeEventHandler(this.CustomerDetailsView_ModeChanging);
// Add the DetailsView object to the Controls collection
// of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView);
}
void CustomerDetailsView_PageIndexChanging(Object sender, DetailsViewPageEventArgs e)
{
// Use the sender parameter to access the DetailsView control
// that raised the event.
DetailsView customerDetailsView = (DetailsView)sender;
// Cancel the paging operation if the DetailsView control
// in edit mode.
if (customerDetailsView.CurrentMode == DetailsViewMode.Edit)
{
e.Cancel = true;
// Display an error message.
int newPage = e.NewPageIndex + 1;
MessageLabel.Text = "Please update the current record before to moving to page " +
newPage.ToString() + ".";
}
}
void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
{
// Clear the message label when the user changes mode.
MessageLabel.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:placeholder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
<asp:label id="MessageLabel"
forecolor="Red"
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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
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.AutoGenerateEditButton = True
customerDetailsView.AllowPaging = true
customerDetailsView.PagerSettings.Position = PagerPosition.Bottom
Dim keyArray() As String = {"CustomerID"}
customerDetailsView.DataKeyNames = keyArray
' Programmatically register the event-handling methods
' for the DetailsView control.
AddHandler customerDetailsView.PageIndexChanging, AddressOf CustomerDetailsView_PageIndexChanging
AddHandler customerDetailsView.ModeChanging, AddressOf CustomerDetailsView_ModeChanging
' Add the DetailsView object to the Controls collection
' of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView)
End Sub
Sub CustomerDetailsView_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs)
' Use the sender parameter to access the DetailsView control
' that raised the event.
Dim customerDetailsView As DetailsView = CType(sender, DetailsView)
' Cancel the paging operation if the DetailsView control
' in edit mode.
If customerDetailsView.CurrentMode = DetailsViewMode.Edit Then
e.Cancel = True
' Display an error message.
Dim newPage As Integer = e.NewPageIndex + 1
MessageLabel.Text = "Please update the current record before to moving to page " & _
newPage.ToString() & "."
End If
End Sub
Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)
' Clear the message label when the user changes mode.
MessageLabel.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:placeholder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
<asp:label id="MessageLabel"
forecolor="Red"
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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Nell'esempio di codice seguente viene illustrato come aggiungere in modo dichiarativo un DetailsViewPageEventHandler delegato all'evento PageIndexChanging 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 CustomerDetailsView_PageIndexChanging(Object sender, DetailsViewPageEventArgs e)
{
// Cancel the paging operation if the DetailsView control
// in edit mode.
if (CustomerDetailsView.CurrentMode == DetailsViewMode.Edit)
{
e.Cancel = true;
// Display an error message.
int newPage = e.NewPageIndex + 1;
MessageLabel.Text = "Please update the current record before to moving to page " +
newPage.ToString() + ".";
}
}
void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
{
// Clear the message label when the user changes mode.
MessageLabel.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogenerateeditbutton="true"
datakeynames="CustomerID"
allowpaging="true"
onpageindexchanging="CustomerDetailsView_PageIndexChanging"
onmodechanging="CustomerDetailsView_ModeChanging"
runat="server">
<pagersettings position="Bottom"/>
</asp:detailsview>
<br/>
<asp:label id="MessageLabel"
forecolor="Red"
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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
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 CustomerDetailsView_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs) Handles CustomerDetailsView.PageIndexChanging
' Cancel the paging operation if the DetailsView control
' in edit mode.
If CustomerDetailsView.CurrentMode = DetailsViewMode.Edit Then
e.Cancel = True
' Display an error message.
Dim newPage As Integer = e.NewPageIndex + 1
MessageLabel.Text = "Please update the current record before to moving to page " & _
newPage.ToString() & "."
End If
End Sub
Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) Handles CustomerDetailsView.ModeChanging
' Clear the message label when the user changes mode.
MessageLabel.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogenerateeditbutton="true"
datakeynames="CustomerID"
allowpaging="true"
runat="server">
<pagersettings position="Bottom"/>
</asp:detailsview>
<br/>
<asp:label id="MessageLabel"
forecolor="Red"
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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Commenti
Il DetailsView controllo genera l'evento PageIndexChanging quando viene selezionato un pulsante cercapersone (un pulsante con la relativa CommandName proprietà impostata su "Page") all'interno del controllo, ma prima che il DetailsView controllo gestisca l'operazione di paging. In questo modo è possibile fornire un gestore eventi che esegue una routine personalizzata, ad esempio l'annullamento dell'operazione di paging, ogni volta che si verifica questo evento.
Nota
I pulsanti pager si trovano in genere nella riga pager di un DetailsView controllo .
Quando si crea un delegato DetailsViewPageEventHandler, 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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