DetailsViewPageEventHandler Delegar
Definição
Representa o método que manipula o evento PageIndexChanging de um controle DetailsView.Represents the method that handles the PageIndexChanging event of a DetailsView control.
public delegate void DetailsViewPageEventHandler(System::Object ^ sender, DetailsViewPageEventArgs ^ e);
public delegate void DetailsViewPageEventHandler(object sender, DetailsViewPageEventArgs e);
type DetailsViewPageEventHandler = delegate of obj * DetailsViewPageEventArgs -> unit
Public Delegate Sub DetailsViewPageEventHandler(sender As Object, e As DetailsViewPageEventArgs)
Parâmetros
- sender
- Object
A fonte do evento.The source of the event.
Um DetailsViewPageEventArgs que contém os dados do evento.A DetailsViewPageEventArgs that contains the event data.
Exemplos
O exemplo de código a seguir demonstra como adicionar programaticamente um DetailsViewPageEventHandler delegado ao PageIndexChanging evento de um DetailsView controle.The following code example demonstrates how to programmatically add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.
<%@ 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>
O exemplo de código a seguir demonstra como adicionar declarativamente um DetailsViewPageEventHandler delegado ao PageIndexChanging evento de um DetailsView controle.The following code example demonstrates how to declaratively add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.
<%@ 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>
Comentários
O DetailsView controle gera o PageIndexChanging evento quando um botão de pager (um botão com sua CommandName propriedade definido como "Page") dentro do controle é clicado, mas antes de o DetailsView controle manipular a operação de paginação.The DetailsView control raises the PageIndexChanging event when a pager button (a button with its CommandName property set to "Page") within the control is clicked, but before the DetailsView control handles the paging operation. Isso permite que você forneça um manipulador de eventos que executa uma rotina personalizada, como cancelar a operação de paginação, sempre que esse evento ocorrer.This allows you to provide an event handler that performs a custom routine, such as canceling the paging operation, whenever this event occurs.
Observação
Os botões de pager geralmente estão localizados na linha do pager de um DetailsView controle.Pager buttons are usually located in the pager row of a DetailsView control.
Ao criar um DetailsViewPageEventHandler delegado, você identifica o método que manipulará o evento.When you create a DetailsViewPageEventHandler delegate, you identify the method that will handle the event. Para associar o evento ao manipulador de eventos, adicione uma instância do delegado ao evento.To associate the event with your event handler, add an instance of the delegate to the event. O manipulador de eventos é chamado sempre que o evento ocorre, a menos que você remova o representante.The event handler is called whenever the event occurs, unless you remove the delegate. Para obter mais informações sobre delegados de manipulador de eventos, consulte manipulando e gerando eventos.For more information about event-handler delegates, see Handling and Raising Events.
Métodos de Extensão
| GetMethodInfo(Delegate) |
Obtém um objeto que representa o método representado pelo delegado especificado.Gets an object that represents the method represented by the specified delegate. |